PrepTest 141, Section 4, 20. In a recent study of stroke patients…

How will the right answer fit in terms of support and conclusion?

Only the right answer will add support for the conclusion in the passage.

Highlight the main conclusion in the passage, if there is one:

glutamate leaking from damaged or oxygen-starved nerve cells is a cause of long-term brain damage resulting from strokes.

[SUPPORT]. [BACKGROUND]. Thus [CONCLUSION].

It should be news to absolutely no one that this conclusion is claiming cause-and-effect. You’re in even better shape if you recognize that the support is just a correlation. The bit that says “if it leaks” doesn’t actually support the conclusion since it never says if the leaking is actually happening. You should expect the right answer to add support for that.

Map the wording of the answers to the wording of the passage:

(A) Any neurotransmitter that leaks…

Cool story. But this still doesn’t say if the leaking is actually happening, so it doesn’t add any new support for the conclusion.

(B) Stroke patients exhibit a wide variety of abnormal chemicals…

This is pretty general info, so it’s not likely to “strengthen” any argument. If anything this just opens the door for “a wide variety” other explanations besides the one in the conclusion.

(C) Glutamate is the only neurotransmitter that leaks…

That’s really fascinating, but again, it doesn’t tell us if the leaking is actually happening.

(D) Leakage…is the only possible source…

Boom. There’s no other way glutamate could have gotten into the blood of the stroke patients in the study. Now I’m ready to agree that leaking is actually happening, and the conclusion is way strengthened.

(E) Nerve cells can suffer enough damage to leak glutamate…

Yah, the passage already said leakage was a possibility, which is all this says. And whether they get “destroyed themselves” or not isn’t mentioned or referenced in the passage.

(D) is the correct answer.

Common pattern/s in this question: This cause-and-effect argument includes the very common mistake of confusing correlation for cause-and-effect.