PrepTest 116

Incorrect. This is the phenomenon being explained, not the explanation, so it's not the main point.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Main Point

Stimulus Summary:
Phenomenon — Many human hormones can raise blood glucose concentrations
Explanation — A metabolic quirk of the brain
Justification — The brain can only use glucose for energy, so if it doesn't have glucose, then you die fast

Answer Anticipation:
Knowing common argument structures on the LSAT is exceptionally helpful in finding the correct answer to this question quickly since it's got a lot of difficult science in it.

This argument very much falls into the phenomenon/explanation category. A phenomenon is raised, and the author's explanation for it serves as the main point. Here, the explanation for the phenomenon about hormones and blood glucose levels is that it's a metabolic quirk of the brain.

The rest of the passage after that justifies the belief that the brain is responsible for the hormones that can independently raise glucose levels. While there is an intermediate conclusion in there (Thus . . . "), that's meant to show that something about the brain and glucose is important to survival, supporting the claim that the phenomenon can be explained by the brain's metabolism.

Let's find an answer reflecting that explanation—the ability of different hormones to independently increase blood glucose levels is because of a metabolic quirk of the brain.

Answer Explanation:
This answer highlights the author's explanation for the phenomenon, which she supports with information about the brain and glucose, so it's the main point and correct answer.

Key Takeaway:
Knowing how certain argument structures work can be very helpful in some of these harder questions, where the content is difficult to understand. Seeing the phenomenon/explanation structure here and knowing that, in such an argument, the author's preferred explanation is likely to be the main point made this question much easier.

Incorrect. Facts such as this will almost always be premises. This fact supports the explanation that it's the brain's metabolism that has driven the development of multiple hormones affecting blood glucose levels.

Incorrect. This is an intermediate conclusion. It does have support in the statement saying that the brain can metabolize only glucose, but it shows the importance of having glucose available in the blood for the brain to function. As such, it supports the conclusion—hence calling it an intermediate conclusion.

Incorrect. This answer is some type of reflection of the premise and intermediate conclusion, not the main point.