PrepTest 158

This doesn't affect the argument at all. The consumer advocate doesn't conclude that pharmaceutical drugs in the food supply will pose a public health risk. Their conclusion only states that pharmaceutical drugs might end up in the food supply. So, even if the scientists are correct and these drug-producing crops won't present any danger to public health, that wouldn't weaken the advocate's conclusion.

Alternatively, if we used the backup plan, we could construct this argument (note that we simplified the premises and answer choice and are using the negated form of the conclusion):

"Scientists now genetically engineer some crops for pharmaceutical use. If pollen from a drug-producing crop drifts into another field, it can fertilize a food crop. The food crop would turn into a drug-producing crop. But, scientists don't think the drug-producing crops will endanger public health in the food supply. So, the drugs will not end up in the food supply."

This argument doesn't sound very convincing. The public health argument in the "But" statement has nothing to do with the conclusion's assertion the drugs won't end up in the food supply.

Whichever approach we use, we can eliminate (A).

This doesn't weaken the consumer advocate's argument. Sure, if pollen is prevented from drifting into other fields, then there isn't a risk of turning a food crop into a drug-producing crop. But what if we let our guard down? What if we can't prevent pollen from drifting into other fields? After all, the consumer advocate didn't say that pollen will definitely drift into other fields and fertilize food crops, converting them into drug-producing crops. The consumer advocate just said it "could happen." Without knowing that we'll always be able to prevent pollen from genetically modified crops from drifting into other fields, we can't say that (B) would weaken the conclusion that there's a "possibility" that drugs end up in the food supply.

Alternatively, if we used the backup plan, we could construct this argument (note that we simplified the premises and answer choice and are using the negated form of the conclusion):

"Scientists now genetically engineer some crops for pharmaceutical use. If pollen from a drug-producing crop drifts into another field, it can fertilize a food crop. The food crop would turn into a drug-producing crop. But, if we prevent pollen from drifting into other fields, then there's no risk of pollen fertilizing food crops. So, the drugs will not end up in the food supply."

This argument isn't awful. Still, the conclusion sounds a bit bolder than the "But" statement would allow. We only know that the drugs will not end up in the food supply if we continuously prevent pollen from drifting into other fields. Who knows if we can do that.

This isn't the worst answer choice in the world, and it's OK if we keep it as a contender. But it's far from perfect, too. It doesn't seem like it prevents drugs from entering the food supply. So, we definitely need to check the remaining answer choices before selecting (B). (Upon checking the remaining choices, we’ll see there is a much better option.)

This doesn't affect the argument. The consumer advocate doesn't conclude that most people will consume the pharmaceutical drugs in the food supply. They only claim thats that pharmaceutical drugs might end up in the food supply. Even if the drug-producing crops are random foods very few people eat, they could still be "in" the food supply.

Alternatively, if we used the backup plan, we could construct this argument (note that we simplified the premises and answer choice and are using the negated form of the conclusion):

"Scientists now genetically engineer some crops for pharmaceutical use. If pollen from a drug-producing crop drifts into another field, it can fertilize a food crop. The food crop would turn into a drug-producing crop. But, the drug-producing corps are not among the most commonly eaten foods. So, the drugs will not end up in the food supply."

This argument doesn't sound very persuasive. The "But" statement doesn't prove that the drugs will not end up in the food supply. It only suggests that few people will each them once they're in the food supply.

Whichever approach we use, we can eliminate (C).

Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Weaken

Passage Summary:
Scientists now genetically engineer some crops for pharmaceutical use. However, drugs can now end up in the food supply. If pollen from a drug-producing crop drifts into another field, it can fertilize a food crop. The food crop would turn into a drug-producing crop.

Strategy Overview:

1. Argument or facts? Always argument, so identify premises and conclusions of argument
2. Anticipate why the premises are not enough to show that the conclusion is true
1. Causal argument? Look for answer choice that:
1. Shows possible alternate cause
2. Shows cause without effect
3. Shows effect without cause
4. Shows the cause and effect are reversed
2. If not causal argument, anticipate ways to worsen problem with argument
3. Use anticipations to select the answer choice that, if true, would weaken argument

Answer Anticipation:
Our ultimate goal is to find the answer choice that weakens the argument. However, it's much easier to do that if we first break down the argument and identify its flaws. Then, weakening the argument is only a matter of finding the answer choice that exploits that flaw.

This question is challenging, in part, because the flaw isn't readily apparent. The consumer advocates' conclusion isn't even bold — they just raise the "possibility" that pharmaceutical drugs can end up in the food supply. So we can’t use the ways we'd normally attack a too-bold conclusion.

So, we may have to just assess the answer choices by asking if they prove that pharmaceutical drugs will not end up in the food supply. To evaluate the answer choices that way, we'll need to really understand the consumer advocate's hypothesis. They believe that if pollen from a drug-producing crop drifts into another field, it can fertilize a food crop. The food crop would turn into a drug-producing crop. And, presumably, the public would consume these drugs unknowingly. The correct answer will probably show why pollen from a drug-producing crop will not be able to drift into another field or fertilize a food crop, or why a food crop willnot turn into a drug-producing crop, or why a drug-producing crop will not be consumed by the public.

Alternatively, we can use the backup plan for this question. To resort to the backup plan, we'll re-read the premises. Then, we'll say, "But," and re-read the answer choice. Finally, we'll say, "So, it may not be true that" and re-read this argument's conclusion. (Or we can just say "So" and then read the negated form of the conclusion.) If that argument makes sense, we'll know the answer choice weakens the argument. If the argument doesn't make much sense, then we can cross that answer choice off. Here's a simplified template we can use for this backup plan (note that we simplified the premise and are using the negated form of the conclusion; because that conclusion says "possibility that the drugs will end up," we need to negate it to "the drugs will not end up"):

"Scientists now genetically engineer some crops for pharmaceutical use.

"If pollen from a drug-producing crop drifts into another field, it can fertilize a food crop.

"The food crop would turn into a drug-producing crop.

"But, [answer choice].

"So, the drugs will not end up in the food supply."

Answer Choice Explanation:
This answer choice shows why the drugs won't end up in the food supply! This answer choice says we don't eat the part of the food crops where the drugs would be present. So, even if drug-producing crops fertilize food crops, converting them to drug-producing plants, the drugs still won't enter the food supply. So, if drug-producing carrots only store the drugs in the roots, the drugs won't end up in the food supply. Only carrot, which has no drugs, would enter the food supply. Therefore, this weakens the consumer advocate's conclusion that these drugs could end up in the food supply.

Further, if we used the backup plan, we could construct this argument (note that we simplified the premises and answer choice and are using the negated form of the conclusion):

"Scientists now genetically engineer some crops for pharmaceutical use. If pollen from a drug-producing crop drifts into another field, it can fertilize a food crop. The food crop would turn into a drug-producing crop. But, the drugs in drug-producing crops are not in any part of the crop used for food. So, the drugs will not end up in the food supply."

This argument sounds pretty good! Yes, the drugs could end up in food crops, but not in the part of the food crop we use for food. So, it's fair to conclude that the drugs will not end up in the food supply.

No matter the approach we used, we can confidently select (D).

Key Takeaway:
We need a very bold answer choice that provides a lot of information to weaken a conclusion expressed with wishy-washy language like "possibility."

This doesn't quite weaken the consumer advocate's conclusion. Yes, scientists could identify the drug-producing crops, but could they do so before those crops entered the food supply? Could they always identify these crops and prevent them from entering the food supply. After all, the consumer advocate didn't say that drugs will definitely enter into the food supply. The consumer advocate just said it "could happen." Without knowing that scientists will always be able to identify the drug-producing crops and prevent them from entering the food supply, we can't say that (E) would weaken the conclusion that there's a "possibility" that drugs end up in the food supply.

Alternatively, if we used the backup plan, we could construct this argument (note that we simplified the premises and answer choice and are using the negated form of the conclusion):

"Scientists now genetically engineer some crops for pharmaceutical use. If pollen from a drug-producing crop drifts into another field, it can fertilize a food crop. The food crop would turn into a drug-producing crop. But, if a food crop would turn into a drug-producing crop, then scientists could identify the drug-producing crop. So, the drugs will not end up in the food supply."

This argument doesn't seem very persuasive! Knowing that scientists can identify drug-producing crops provides no assurance that the crops won't end up in the food supply.

Whichever approach we use, we can eliminate (E).