The best statement of the main idea of this passage is that ______.
A. human brains differ considerably
B. the brain a person is born with is important in determining his intelligence
C. environment is crucial in determining a person’s intelligence
D. a person who is handicapped environmentally will never attain the level of intelligence of which he is capable
正确答案：C
答案为C根据第二段的中心得出选项C为正确答案
