Lake Victoria Is Famous for Its Variety of Cichlid Fishes

Lake Victoria is famous for its variety of cichlid fishes.In fact,they offer the most diverse assembly of vertebrates presently known to science.One trait that scientists have focused on as one possible reason for their adaptability is

A) a second set of scales that lie beneath the top outermost scales.
B) a second set of jaws in their throats.
C) gill arches that are not covered by an operculum,which prevents hiding places for gill parasites.
D) digestive tracts that are able to process most substrates,which has eliminated the need for feeding specialization.
E) ability to change color in relationship to their environment.