8. What did Blaustein and Hays conclude from their research?
a. UV radiation damages DNA in most kinds of amphibian.
b. Changes in natural surroundings cause most species to disappear.
c. Eggs of amphibian species likely to be affected sunlight were not killed when sunlight was screened.
d. The difference in the ability to endure sunlight of the eggs of different species of amphibians not significant.