One Reason That Kinsey's Research on Sexual Orientation Is Important

One reason that Kinsey's research on sexual orientation is important is because

A) he was able to prove that every individual is bisexual.
B) it challenged the dichotomized model of sexual orientation.
C) it was the first study to find that homosexual subjects were just as well adjusted as heterosexual participants.
D) he did a large-scale observational study that showed that homosexuality indicated a person's sexual orientation.