【单选题】

The author is primarily concerned with
A．(A) disproving the view that bipedalism alone can account for the human brain's evolution

B．(B) describing a relationship between the acquisition of an improved diet and the development of the human brain
C．(C) contrasting the characteristics of Homo and his primate ancestors
D．(D) analyzing the evolutionary basis for the development of the modern human diet
E．(E) demonstrating the importance of brain growth in developing human social behavior, foraging tactics, and better diet