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
nonamphibian 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.