Most trails seen here were forged

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands

i think its white blood cells

i hope this

actually the answer is c

it should be d) transitional fossils.

they show the gradualism of evolution throughout a period of time