57. Extinction is a process that can depend on a variety of ecological, geographical, and physiological variables.
These variables affect different species of organisms in different ways, and should, therefore, yield a random pattern of extinctions. However, the fossil record shows that extinction occurs in a surprisingly definite pattern, with many species vanishing at the same time.
Which of the following, if true, forms the best basis for at least a partial explanation of the patterned extinctions revealed by the fossil record?
(A) Major episodes of extinction can result from widespread environmental disturbances that affect numerous different species.
(B) Certain extinction episodes selectively affect organisms with particular sets of characteristics unique to their species.
(C) Some species become extinct because of accumulated gradual changes in their local environments.
(D) In geologically recent times, for which there is no fossil record, human intervention has changed the pattern of extinctions.
(E) Species that are widely dispersed are the least likely to become extinct.
A is the best answer.
Choice A, the best answer, asserts that some environmental disturbances can be so widespread as to cause the extinction of numerous species. This fact helps to explain why the fossil record frequently shows many species becoming extinct at the same time, despite the variety of factors that can cause a species to become extinct.
想请教各位，小的不懂为什么A选项可以解释文中矛盾之处，另外，也不太了解highlight的解释，请各位指教，谢谢！！
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