Logical reasoning PrepTest 152 · Section 4 · Question 19

Whether the ants get a long or short period of safety from the resin doesn't tell us their motivation behind using it. They could just as easily use it for a short period of safety as a long one.

If a premise informed us that the bacteria was more present at certain times of the year rather than others, this answer might be relevant.

Other ants may or may not be susceptible to bacteria that is disinfected by the resin. Without knowing that, the answer to this question isn't helpful in analyzing the argument.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Argument Evaluation

Stimulus Summary:
Resin is in wood ant nests. Resin kills deadly ant bacteria. The wood ants probably use resin to protect themselves from disease.

Answer Anticipation:
This is a classic jump between correlation and causation. The author starts with a correlation—resin is in ant nests; resin is a disinfectant. Then, the author states that one of those things motivates (or causes) the other.

Whenever an author selects a motivation, it's suspect, especially when the subject is an animal (did the author interview the ants about their motivations?). Maybe it's just a coincidence that the ants use something that is a disinfectant, but they really use it for another reason. We should be on the lookout for some other reason as we analyze the answer choices.

Answer Explanation:
This answer asks about another potential motivation for using the resin. It's possible the ants use it because it's a good building material, and any disinfectant qualities are merely incidental. If the resin does confer structural benefits, then it hurts the argument that they use it for its disinfectant properties. If it doesn't, then it helps that argument. This is the answer.

Key Takeaway:
For Argument Evaluation questions, it can sometimes be helpful to "answer" the question in the answer choice with Yes and No to see what impact it has on the argument. The correct answer will strengthen the argument with one answer, and weaken it with another.

It doesn't matter how the disinfectant properties came about, just that they did.