Logical reasoning PrepTest 110 · Section 2 · Question 19

Incorrect. There's no information allowing this comparison in the stimulus. Maybe if it was noted that only gastrin triggers acid secretion we would be able to find some support for this answer, but the stimulus notes only that it triggers such secretions, not that other things don't.

Incorrect. While taking too much CC can result in impaired kidney function, that doesn't tell us anything about the "average" level of function or what might lead different populations to have impaired function. It's possible that people who stringently avoid taking that much CC do so because they have bad kidneys thus making the opposite of this answer true.

Incorrect. This answer is tempting because we know that CC neutralizes stomach acid, but at a certain dose starts stimulating the production of it. However, there's no indication that taking super large doses wouldn't neutralize all stomach acid, including any stimulated by the gastrin, whereas lower doses only neutralizes some of it.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Must Be True

Stimulus Summary:
Calcium Carbonate (CC):
(1) Neutralizes stomach acid
(2) Increases blood calcium levels, impairing kidney function
(3) Half a gram can lead to gastrin production, which triggers acid secretion
Therefore — People should avoid taking more than half a gram of CC

Answer Anticipation:
Remember—Must Be True questions that include an argument should still be treated as presenting facts in the stimulus, including the conclusion. Don't treat the conclusion as an uncertainty as you would in other questions!

Here, the stimulus is all about causality—it lists out several effects of calcium carbonate. As such, we should head into the answers expecting it to deal with this causality.

Is there anything we can specifically anticipate? There is, though if you missed it, it's not a big deal, as you could still have found the correct answer by focusing on the effects. However, whenever a Must Be True question presents information that seems paradoxical or counterintuitive, there's a good chance that the correct answer will bring it up. Why? Because your gut is going to be that the answer is wrong since it seems contradictory.

Here, it's noted that a CC both neutralizes stomach acid and, at a certain level (half a gram+), triggers acid secretion. Those effects seem to counter each other, so that may play a role in the correct answer.

Answer Explanation:
This answer is nice and weak—"can . . . contribute"—which is generally going to be easier to find support for especially when dealing with causality. And we do know that CC neutralizes stomach acid (causally contributing to neutralization) and at half a gram or more stimulates the production of gastrin (causally contributing to the secretion of stomach acid). This answer is thus supported by the stimulus and so it's the correct answer.

Key Takeaway:
Must Be True questions that present information that could be seen as contradictory or unintuitive will often have answers reflecting that information. Why? Because someone reading that answer without understanding the stimulus will rule it out because it sounds outlandish and thus it's a great "hidden" answer (the opposite of a trap answer—one that sounds wrong but is actually right). Knowing these patterns can prevent you from eliminating correct answers!

Incorrect. The stimulus establishes the causality in the other direction—higher calcium levels in the blood leads to impaired kidney function—and so this answer is unsupported.