PrepTest 146

Incorrect. Cocoa is noted as being high in flavonoids, and Kuna who move to the mainland stop drinking as much cocoa, but that doesn't mean they don't get flavonoids from some other source. It also doesn't even mean that cocoa isn't widely available—it might be available and yet there's some other reason the Kuna stop consuming it at the same level.

Incorrect. There's no discussion of the motive behind cocoa consumption, so we can't assume one. They may drink it because it's delicious, or it's a part of the culture to have cocoa instead of, say, coffee.

Incorrect. If anything, this answer is contradicted because the subset of the population that moved to the mainland doesn't have a low incidence of high blood pressure.

Incorrect. There's no discussion of any other people in the stimulus, so this answer/comparison is out of scope.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Kuna on Panamanian islands:

Low incidence of high blood pressure
Drink several cups of cocoa/day

Kuna on mainland:

Normal incidence of high blood pressure
Don't drink a lot of cocoa

Cocoa Ð Minimally processed, high in flavonoids

Answer Anticipation:
The stimulus provides a lot of comparisons between the Kuna who are still on the islands versus those on the mainland, so those will likely be relevant to the correct answer.

One other point—the argument seems to be strongly hinting that the cocoa is causing the lower incidence of high blood pressure. That's based on a correlation, so causality can't be proven and we should be wary of a causal answer, but there's not much else to be inferred here, so we'll have to at least be open to that answer—especially since it controls for a lot of variables by having the Kuna on the mainland be individuals who moved there—so they were a part of the same population that remained on the island and still has that low incidence of high blood pressure.

Answer Explanation:
While normally we wouldn't select a causal answer when the stimulus is presenting correlations, the other answers are all out of scope or contradicted, and correlation does support causation. There's a strong enough correlation here to say that this statement is strongly supported as the question stem asks for. See the Takeaway for a longer discussion.

Key Takeaway:
Normally, we wouldn't pick a causal answer in a Must Be True question that had mere correlations in the stimulus. However, a few things here let us feel comfortable doing so:

(1) All the other answers were bad
(2) This is a Most Strongly Supported stimulus, not a pure Must Be True one
(3) The stimulus controlled for a lot of variables by using Kuna from the same population, and showing that a certain group moved from one area to another, losing the cause and thus the effect