哪位nn能不能指点一下？38. Amphibian populations are declining in numbers worldwide. Not coincidentally, the earth’s ozone layer has been continuously depleted throughout the last 50 years. Atmospheric ozone blocks UV-B, a type of ultraviolet radiation that is continuously produced by the sun, and which can damage genes. Because amphibians lack hair, hide, or feathers to shield them, they are particularly vulnerable to UV-B radiation. In addition, their gelatinous eggs lack the protection of leathery or hard shells. Thus, the primary cause of the declining amphibian population is the depletion of the ozone layer.
Each of the following, if true, would strengthen the argument EXCEPT:
A. Of the various types of radiation blocked by atmospheric ozone, UV-B is the only type that can damage genes.
B. Amphibian populations are declining far more rapidly than are the populations of non-amphibian species whose tissues and eggs have more natural protection from UV-B.
C. Atmospheric ozone has been significantly depleted above all the areas of the world in which amphibian populations are declining.
D. The natural habitat of amphibians has not become smaller over the past century.
E. Amphibian populations have declined continuously for the last 50 years.
宝典里答案是A，可是详解里答案是D。到底选哪个呀？ 哪位nn能不能指点一下？
谢谢!
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