Charles Darwin's observations that finches of different species on the Galapagos Islands have many similar physical characteristics supports the hypothesis that these finches A all eat the same type of food. B acquired traits through use and disuse. C descended from a common ancestor. D have the ability to interbreed.

C descended from a common ancestor

Explanation:

Darwin's voyage which included an exploration of the Galapagos Islands led him to discover that there are several different species of finches on the various Islands of the Galapagos. More interesting is the fact that, these finches he found on the various Islands of the Galapagos have similar physical characteristics with that of the finches from other parts of South America compared to those in other islands of the world. This finding supports the hypothesis that these finches descended from a common ancestral population of South America birds that eat seeds.