To Date, Research on the Possible Biological Bases of Same-Gender

To date, research on the possible biological bases of same-gender orientation suggests that

A) among identical twins, the rate of both having same-gender orientation is 48 to 52 percent.
B) any genes that influence sexual orientation occur on the Y chromosome.
C) genes play as much of a role in sexual orientation as they do in determining height.
D) the influence of genes on sexual orientation is slight.