One Recent Study of Gay Males Who Have Brothers Found

One recent study of gay males who have brothers found that

A) birth order has no effect on sexual orientation.
B) the greater the number of brothers, the lower the likelihood that a man will be gay.
C) the greater the number of older brothers, the higher the likelihood that a man will be gay.
D) the greater the number of younger brothers, the higher the likelihood that a man will be gay.