PrepTest 127, Section 3, Question 11
The sun emits two types of ultraviolet radiation(28 more words not shown)
Which one of the following(7 more words not shown)
- ASince about ten(19 more words not shown)
- BMost people whose(17 more words not shown)
- CThe specific cause(12 more words not shown)
- DPeople who wear(26 more words not shown)
- EUntil about ten(30 more words not shown)
Reading the argument
Keep the two types of radiation separate. The passage connects UV-A with premature wrinkles and UV-B with sunburn. We aren't being given an argument to attack; we are being given facts to connect.
Before the change about ten years ago, sunscreen protected against UV-B but not UV-A. Translate that into the effects we just learned: the old sunscreen protected against the radiation that causes sunburn, but not against the radiation that causes premature wrinkles.
What we’re looking for
That gives us a straightforward prediction for the best-supported answer. Wearing sunscreen before that change did not provide protection against the wrinkle-causing radiation. That doesn't mean every person who used the old sunscreen was guaranteed to develop wrinkles. It means the sunscreen did not provide this particular protection.
Working the answers
- A
Better protection could make sunscreen more attractive, but that doesn't establish that more people used it every time they went into the sun. Perhaps prices rose at the same time, or people's habits simply stayed the same. We have information about the product's protection, not a measured change in consumer behavior.
- B
We aren't told that sun exposure is the only cause of premature wrinkles. Other factors, such as genetics, could be involved. Also, people who wore the older sunscreen were still exposed to UV-A, so even sun-related wrinkles would not establish that someone went without sunscreen. We cannot infer this claim about most people with wrinkles.
- C
Knowing a cause and being able to prevent its effects are different things. Researchers might have known that UV-A caused premature wrinkles well before they could make an effective protective sunscreen. The date of the product change doesn't establish when the cause was discovered.
- D
The older sunscreen already protected against UV-B, the radiation connected with sunburn. The passage identifies the missing protection as UV-A protection. It doesn't tell us that today's sunscreen provides better protection against sunburn than the old sunscreen did.
- ECorrect
For people with the same amount of sun exposure, wearing the older sunscreen offered no protection against the UV-A radiation associated with premature wrinkles. That supports the comparison in E: before the change, sunscreen users were no less likely to have that damage than nonusers with equal exposure. Protection against sunburn did not supply protection against the other kind of damage.
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