Which adaptation makes bipedalism possible?

A. opposable digits

B. large brain

C. foramen magnum in back of skull

D. elvis rotated inward

Bipedalism is the ability for a creature to walk on two legs. Beings such as humans are able to walk on their two back legs to to an evolution of their pelvis. The pelvis bone of humans are rotated inward unlike that of other animals. That is the greatest adaptation to allow humans to walk on their back legs. So, the correct answer is D.