In His Book "Men Are from Mars, Women Are from Venus

In his book "Men Are from Mars, Women Are from Venus," Gray writes that men and women almost seem to be from different planets, speaking different languages, and needing different nourishment. Social science research suggests that:

A) this statement is correct, i.e., the difference between the average man and the average woman is large, and there is almost no overlap between the sexes at all.
B) this statement is correct because the range of behavior among members of a given sex is small compared to the average difference between the sexes.
C) sex differences are statistically real but actual differences remain to be demonstrated.
D) men and women are much more similar than different on most of the dimensions and topics of interest to relationship science.