The correct option is C Both A and B
Missing links or transitional species are those intermediate species in the line of evolution, that exhibit characteristics common to both their immediate ancestral and descendant groups. These organisms are called “transitional species” because after the discovery of their fossils, they have been found to bridge the gap between two adjacent evolutionary groups, thus, acting as connecting links. Archaeopteryx for instance, is a transitional species that exhibits both reptilian and avian features. The name "missing links" is given when there seems to be no "linking" species (transitional species) between adjacent taxonomic groups, which is a situation that could arise during evolutionary studies. In other words, "missing link" refers to a perceived gap in the evolutionary record. Once these "links" have been identified, the term no longer makes sense, because it is not missing anymore! They then, come to be known as "transitional species".