What is the main purpose of the passage？A．To outline the research findings on the brain st

What is the main purpose of the passage？

A．To outline the research findings on the brain structure.

B．To explain the link between brain structure and gender differences.

C．To discuss the various factors that cause brain differences.

D．To suggest new areas in brain research.

请帮忙给出正确答案和分析，谢谢！