Assume that you have chosen to research a topic for your biology class and you have become interested in studying the abuse of performance-enhancing drugs by male athletes. the first thing you learn is that many athletes use anabolic-androgenic steroid hormones. males produce one called testosterone, and an appropriate physiological concentration of testosterone keeps the production of sperm at nearly constant levels. you also learn that a consequence of injection of testosterone is suppression of sperm production. why do you suppose this is true? a. excess testosterone inhibits the activity of lh and fsh, neither of which is needed for sperm production. b. the excess testosterone can feed back and inhibit certain steps in spermatogenesis, resulting in lowered sperm counts. c. excess testosterone initiates the formation of diploid sperm. d. excess testosterone causes the release of more gnrh.