Iretract my original question, so instead;

which of the following scientists did not contribute to the idea of natural selection?
a) charles darwin
b) alfred russel wallace
c) both a and b
d) none of the above

The scientist that did NOT contribute to the idea of natural selection is none of the above. The answer is letter D. Both Charles Darwin and Alfred Russel Wallace contribute to the natural selection and are biologist. Darwin hypothesized  his theory of evolution while Wallace supplied Darwin with birds for study only to found out that both have the same hypothesis regarding natural selection.