Similarities in the structures of two different species provide evidence that the species evolved from a common ancestor. This type of evidence includes similar structures that have different functions. Which of the following pairs of features have a similar structure but have a different function in each organism?

a. a dolphin fin and a shark fin.

b. human fingernails and monkey fingernails.

c. the front leg of a cat and a wing of a bat.

d. the wing of a bumble bee and the wing of a bird.