The Principal Point of Darwin's Theory of Evolution by Natural

The principal point of Darwin's theory of evolution by natural selection is that

A) long-term heritable changes in organisms are caused by use and disuse.
B) mutations that adapt an organism to a given environment always arise in the greatest frequency in the organisms that occupy that environment.
C) mutations are caused by all sorts of environmental influences.
D) survival of characteristics in a population depends on a favoring of some forms of a given trait over others in nature.
E) mutations mostly have favorable effects.