PrepTest 153, Section 2, Question 5
One theory concerning the importance of vitamin C(54 more words not shown)
Which one of the following(8 more words not shown)
- ASome doctors believe(13 more words not shown)
- BSome doctors believe(12 more words not shown)
- CSome doctors believe(14 more words not shown)
- DSome doctors believe(14 more words not shown)
- ESome doctors believe(17 more words not shown)
Reading the argument
Vitamin C helps with collagen. Why does that make these doctors think it can help with illness?
We should first keep the claim's status clear. The passage gives a theory about vitamin C, not a demonstrated fact about every effect it has. And even if the theory is right, a crucial role in collagen production doesn't mean vitamin C has no other roles.
Still, the doctors are using this particular role as their reason for expecting a treatment benefit. There has to be a connection in their thinking. If maintaining collagen had nothing to do with the symptoms in question, the collagen theory wouldn't explain why they thought vitamin C could help.
What we’re looking for
That's the broad prediction I'd bring to the most-supported question: these doctors appear to believe collagen is relevant to some common illnesses. We're inferring what their reasoning commits them to, not deciding whether the treatment actually works.
Working the answers
- ACorrect
This carries our prediction one step further. Where is collagen found? Almost exclusively in connective tissue and bones. The doctors think vitamin C helps maintain that protein, and on that basis they think it can help with symptoms. That points to a belief that some illnesses affect those tissues or bones.
Follow the whole connection: vitamin C helps maintain collagen; collagen belongs chiefly to these parts of the body; supporting it is supposed to help with some illnesses. A identifies the link between the illnesses and those parts. It stays with 'some doctors believe,' so we don't have to establish the medical theory as fact.
- B
Something can play a crucial role without doing the job alone. Producing and maintaining collagen might require vitamin C along with other substances. The doctors' reasoning does not identify vitamin C as the only substance involved, and we don't need to supply names of other substances to see that limitation.
- C
This changes the relationship. We were told that vitamin C may help maintain collagen in tissues and bones, not that strengthening those tissues and bones improves the body's ability to use vitamins. The latter would need its own support. It isn't a restatement of the proposed treatment explanation.
- D
'Useful' is much weaker than 'most effective.' A doctor could believe vitamin C provides some relief while another treatment works better. Nothing in the explanation compares treatments or establishes a winner, so we cannot attribute that stronger belief to the doctors.
- E
This tries to make the collagen explanation cover every illness that vitamin C can help. But vitamin C might help some illnesses through other effects. Even if these doctors connect some illnesses with collagen, it doesn't follow that they think every vitamin-C-responsive illness deteriorates connective tissue and bones. A makes the limited connection; E turns it into an unsupported universal rule.
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