Human Embryos and Fish Embryos Share a Number of Features

Multiple Choice

Human embryos and fish embryos share a number of features.Why?

A) Humans and fishes share a common ancestor.
B) All embryos share a similar environment and have acquired similar features via directional selection.
C) Mutations in human and fish embryos have caused them to look alike.
D) Humans and all other vertebrates, including fishes, have identical sets of genes; the differences between the various species are caused by the patterns and timing of gene activation.