How Did Charles Darwin's Original Hypothesis That Organisms Evolved by Natural

How did Charles Darwin's original hypothesis that organisms evolved by natural selection become an important scientific theory?

A) He wrote a book about it and it was marketed well, so the public bought into it.
B) He was a famous scientist and so was respected enough by his colleagues that they believed what he said and accepted it.
C) He and other scientists in many fields of science have tested it over and over again and it's never been disproved, only supported by the evidence they've found.
D) It can't really be tested but it just makes sense
E) Good timing and luck. People were seeking an explanation for the diversity of life on Earth and Darwin happened to provide one that seemed reasonable.