Both Alfred Russel Wallace and Charles Darwin Traveled Extensively and Were

Both Alfred Russel Wallace and Charles Darwin traveled extensively and were struck by the strong patterns they observed in the geographic distribution of nature's diversity. Which of the following observations did Wallace make?

A) Similar species tended to be widely separated geographically and occupied widely different times in geologic history.
B) Geographic features seem to play an important role in the clustering of dissimilar, nonrelated species; these dissimilar species clustered together in time and space.
C) Geographic features seem to play an important role in the clustering of similar, closely related species, and these similar species clustered together in time and space.
D) Wallace observed that geographic distribution of species appeared to be random, correlating with the random nature of genetic mutation.