The amino acid sequence of the protein cytochrome c is compared between three different species: gray whale, hippo, and elephant. It is found that gray whale differs from hippo by 5 amino acids, hippo differs from elephant by 12 amino acids, and gray whale differs from elephant by 30 amino acids. From these data, you could hypothesize that __________.
a. These three species are not related.
b. Hippos are most closely related to elephants.
c. Gray whales are most closely related to hippos.
d. Elephants are most closely related to gray whales.