The following image shows a cladogram for some marine animals.

Based on the cladogram, what statement correctly compares two animals?
A.
A crab and a sea turtle both use lungs to breathe.
B.
A sea turtle has mammary glands, but a dolphin does not.
C.
A dolphin has an internal skeleton, but a shark does not.
D.
A crab and a shark both have skeletons.