Answer
d. morphological divergence
Work Step by Step
With morphological divergence, a structure in a common ancestor appears different in lineages coming from this common ancestor. Take, for example, a human arm, a bat's wing, a chicken wing, and a porpoise's fin. The common ancestor had a forelimb that changed morphologically into each of these modified forelimbs. In some organisms, certain bones were eliminated altogether. Some parts, however, were highly conserved and seen in some form in lineages traced to this common ancestor.
