Logical reasoning PrepTest 138 · Section 3 · Question 6

Correct. Argument or Facts:
Facts

Question Type:
Paradox

Stimulus Summary:
Vitamin C is an antioxidant, protecting the body from oxygen that can trigger illness, so doctors recommend it to people, including those with ailments.
Doctors discourage some cancer patients from taking it.

Answer Anticipation:
We've got a paradox on our hands. Vitamin C can prevent sick people from getting sicker, and it protects people from damaging types of oxygen. This might lead you to expect doctors would recommend it for cancer patients, but there are some cancer patients that are being discouraged from taking the vitamin.

As with many Paradox questions, this scenario involves an implicit comparison between the people that doctors recommend vitamin C to, and those they don't. Since the doctors have a different recommendation for the cancer patients, there must be something relevantly different about them that would justify that recommendation. Something about vitamin C must interact with them and their disease in a way that differs from how it interacts with other illnesses.

This anticipation isn't specific, but that's fine! Clearly defining what the correct answer has to do will allow us to be flexible as we approach the answer choices.

Answer Explanation:
This answer highlights something unique to cancer patients that would make vitamin C inadvisable. If cancer therapies are interfered with by vitamin C, then it makes sense that doctors wouldn't recommend it for these patients.

Key Takeaway:
Paradox questions frequently feature comparisons, either explicit or implicit. When the paradox is based on a comparison between groups, identify if it's a difference or a similarity. In general, unexpected differences are explained by relevant differences, and unexpected similarities are explained by relevant similarities.

Incorrect. The paradox is around why doctors don't recommend vitamin C for cancer patients, people who already have cancer, so this answer about preventing cancer is out of scope.

Incorrect. This answer might explain why vitamin C wouldn't help cancer patients fight cancer, it doesn't explain why doctors are discouraging these patients from taking vitamin C since it does have some health benefits. Even if it didn't have those benefits, vitamin C not treating cancer would be a reason not to recommend it, not to discourage it—a subtle distinction, but still a distinction.

Incorrect. If anything, this makes the paradox worse—vitamin C is noted as helping maintain overall health, so this answer suggests cancer patients should take it to increase their chances for a full recovery.

Incorrect. Similar to (C), this answer might provide a reason that doctors wouldn't recommend taking vitamin C, but since it doesn't have a noted downside, it doesn't explain why they would actively discourage its use.