Complex Tool Use, Spoken Language, and Complex Foraging Strategies Were

Complex tool use, spoken language, and complex foraging strategies were all important hallmarks of human evolution. Current thinking is that each of these was a consequence of:

A) bipedalism and freeing the hands from locomotion.
B) increasing body size and release from predation.
C) increasing brain size and the development of culture.
D) increasing body size and nomadic lifestyle.
E) None of the answer options is correct.