Which adaptation makes bipedalism possible? opposable digits large brain foramen magnum in back of skull pelvis rotated inward

The right option is; pelvis rotated inward

Bipedalism is a type of terrestrial locomotion in which an organism moves by using its two legs or feet. Running, standing, walking, or jumping are the types of bipedal movement . Organisms that use this type of locomotion include humans, chimpanzees, pangolins, spider monkeys, kangaroo rats and mice, and capuchins. The inward rotation of the pelvis makes bipedalism possible.

i believe it would cause an increase of percipitation, though i could be wrong. so i would say b is the answer.