The Following Figure Shows the Vertebrates and Arthropods as Being

The following figure shows the vertebrates and arthropods as being distantly related,yet each has features,such as limbs and jaws,seen in no other groups.How can such obvious similarities be disregarded in favor of embryological development as a basis for classification?

A) The decision to overlook certain features reveals the arbitrary nature of classification and explains why there is so little agreement among taxonomists.
B) Taxonomists have not disregarded limbs; they were likewise inherited from a common ancestor but secondarily lost by the mollusks, annelids, and echinoderms.
C) Embryos are securely protected during development and experience little selection pressure; shared inherited features are best explained by a common ancestor.
D) Examination of the embryos of all animals with body cavities reveals limbs, but they are unnecessary for some lifestyles and so they degenerate.