Which of the Following Statements Describes Our Current Understanding of Differences

Which of the following statements describes our current understanding of differences in the structure of human female and human male brains?

A) Male and female brains are identical.
B) Some suggestions of differences have been reported, but none of the differences has proven to be replicable.
C) Many structural differences have been documented.
D) The female frontal cortex is substantially larger than the male counterpart.
E) The male frontal cortex has an extra layer.