Which best describes the lower body structures of humans and chimpanzees?
a. the big toes of humans and chimpanzees are enlarged.
b. the human foot has two arches, but the chimpanzee foot only has one.
c. human knees are very mobile, but chimpanzee knees are stabilized by tendons.
d. the blades of the human pelvis are not rotated inward like those of the chimpanzee

The answer is b in edge.n.ui.ty

Explanation:

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.