Label all of the letters A-J.

I'm willing to help but, what is the question and what are the labels we are supposed to be labeling all of the letter from A to J?

it's c. (to reduce the greenhouse effect/carbon gasses)

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