How Did Masters and Johnson Refute Freud's Theory of Clitoral

How did Masters and Johnson refute Freud's theory of clitoral and vaginal orgasms?

A) They showed that women had less powerful sex drives than men, and therefore were less likely to have multiple orgasmic methods.
B) They showed that an orgasm always consists of contractions of the orgasmic platform, whether the stimulation is clitoral or vaginal.
C) Through a randomized controlled study, they proved that the female body is physiologically incapable of experiencing vaginal orgasms.
D) Through a randomized controlled study, they proved that the female body is physiologically incapable of experiencing clitoral orgasms.