One Way in Which Homosexual and Heterosexual Men Differ Biologically

One way in which homosexual and heterosexual men differ biologically, on the average, is that (according to one study)

A) heterosexual men reach puberty three or four years earlier.
B) one structure in the hypothalamus is larger for heterosexual men.
C) heterosexual men have twice as high estrogen levels.
D) homosexual men have twice as high estrogen levels.