Which of the following, if true, provides the strongest support for the argument? A. Even in those regions where there has been no significant increase in ultraviolet radiation, only a small proportion of the frog eggs that are laid ever hatch. B. In areas where there has been the least decline in frog populations, populations of species of insects that frogs eat have decreased. C. The eggs of frog species whose populations are declining tend to have higher concentrations of damaging pesticides than do the eggs of frog species whose populations have not declined. D. In many places where turtles, which lay eggs with tough, leathery coverings, share habitats with frogs, turtle populations are also in decline. E. Populations of frog species that hide their eggs beneath rocks or under sand have declined considerably less than have populations of frog species that do not cover their eggs.