Logical reasoning PrepTest 111 · Section 1 · Question 3

Correct. Argument or Facts:
Argument

Valid or Flawed:
Valid

Question Type:
Main Point

Stimulus Summary:
Phenomenon — More women than men suffer from Alzheimer's
Old explanation — Women live longer than men, and Alzheimer's primarily affects the elderly
Conclusion — This theory may be wrong
Support — A study shows something about estrogen and testosterone

Answer Anticipation:
Don't work past the answer in Main Point questions!

Here, the argument starts off with a phenomenon and it brings up what has "often been" the explanation for it. That phrasing suggests that the author is going to pivot away from that explanation and she does ("but") to say that it may be wrong. The author's opinion of an opposing point is generally the main point of the argument so we have a great candidate for the main point in this pivot statement.

The pivot statement being the main point is backed up by the argument immediately going into a study—and studies are almost always support for the main point. That study suggests that the real explanation for the discrepancy is related to estrogen levels so we can pull that into our anticipation:
It may be estrogen levels rather than longevity that explains why more women than men get Alzheimer's disease.

Answer Explanation:
This answer matches our anticipation exactly. It provides the author's preferred explanation for the phenomenon while also matching the logical force of the conclusion ("may").

Key Takeaway:
Knowing common patterns on the exam will help you more quickly break down arguments. Here there are two. First the argument falls into a phenomenon/explanation pattern in which case the author's opinion of an explanation or her preferred explanation will almost always be the main point. Second the argument has a traditional or commonly held view and an argument with one of those almost always pivots away from it.

Incorrect. If anything, this is established as background information in the first sentence.

Incorrect. This answer may be an implication of the information from the study, but it's never stated by the author and doesn't line up with the conclusion as stated, so it's incorrect.

Incorrect. This is a part of the results of the study, which backs up the argument's conclusion that an explanation other than longevity may explain the different rates of Alzheimer's.

Incorrect. The stimulus notes that testosterone "may help safeguard" men against Alzheimer's which is very different from saying it's necessary in preventing it.