Logical reasoning PrepTest 133 · Section 3 · Question 24

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen with Sufficient Premise

Stimulus Summary:
Age causes a deficiency in the active form of vitamin D which is necessary for calcium absorption so causes a calcium deficiency which causes a rise in blood pressure. A glass of milk can fix the calcium deficiency, so old people drinking milk can lower their blood pressure.

Answer Anticipation:
That's a lot of causality, with a conditional statement thrown in ("vitamin D is needed . . . "). Causality chains together the same as conditional statements, and our summary reflects that.

Looking at the stimulus, the argument brings up a "cure" for high blood pressure for the elderly. Since the premises are causal, they can support a causal conclusion, and whenever a conclusion talks about cures, it's talking causality since a cure causes some type of benefit in the person taking it that resolves an issue.

It is established that a calcium deficiency can contribute to high blood pressure. When a cause is removed, there should be some decrease in the effect, so fixing the calcium deficiency should lower blood pressure. So where's the gap?

Well, the cure isn't raising calcium levels—it's drinking milk, which has enough calcium to make up for a calcium deficiency. That doesn't guarantee the calcium is absorbed—and now we're going to circle back to that conditional statement. The stimulus notes that vitamin D in some form is "needed" for calcium to be absorbed. It won't do much good if that calcium in the milk just passes through the system. That milk also has to have vitamin D in order to get absorbed, fix the calcium deficiency, and lower blood pressure. Let's find an answer stating that the milk also contains the substance needed to get that calcium absorbed.

Answer Explanation:
This answer establishes that the milk has enough calcium to fix any underlying deficiency and enough vitamin D (and any other substance) to get that calcium absorbed into the system. With that established, a factor in rising blood pressure is addressed, and the conclusion is properly drawn.

Key Takeaway:
Causal statements can chain together to support causal conclusions, and removing a cause should result in the effect decreasing, as well. Additionally, when a conditional statement/strong statement is thrown into the middle of an argument, it's likely going to be relevant in finding the correct answer, so be sure to note it.

Incorrect. This answer might establish that the milk itself won't raise blood pressure, but without establishing that it will help lower blood pressure with calcium that's actually absorbed, the conclusion is still unsupported.

Incorrect. The argument establishes that the calcium deficiency is caused by a deficiency in vitamin D—that deficiency would have to be alleviated, not just not made worse, for the conclusion to hold.

Incorrect. There's no indication that milk contains "high" quantities of calcium, just enough of it to overcome an underlying deficiency.

Incorrect. This answer doesn't address whether milk will help to fix the vitamin D deficiency that would allow the calcium to be absorbed.