Why Has Gender Testing for Athletic Competition Tended to Focus

Why has gender testing for athletic competition tended to focus on women?

A) Fear that men would masquerade as women to win competitions
B) Fear that women would masquerade as men to win competitions
C) Fear that women and men would end up competing against each other
D) It was thought to be easier to test women than men.
E) It was thought that athletic women were less likely to be honest.