There Is Some Debate Regarding the Recognition of Reptiles as a Legitimate

There is some debate regarding the recognition of reptiles as a legitimate lineage because

A) reptiles are no longer a dominant group nor particularly important to life on Earth.
B) reptiles and birds share a single common ancestor but are placed into different phyla within the Linnaean hierarchy.
C) reptiles reproduce using eggs, but are not grouped with other organisms sharing a similar reproductive method such as the fish and amphibians.
D) as a single group the reptiles contains too many species.