Answer
d.
Work Step by Step
Although homologous structures in several organisms may appear different in terms of size, shape, and function, all evolved from the same structure in the ancestor organism. This is the case in vertebrate forelimbs. Despite the differences in appearance and function among the forelimbs of pterosaurs, chickens, penguins, porpoises, bats, humans, and elephants, the internal structure and position of the parts in relation to one another is the same in each species.
