Answer to Question 1
ANS: D
The acidity of the vas deferens and the vagina interferes with sperm motility. Because prostate fluid is alkaline, it alters the pH of the vas deferens and the vagina to create an environment that enhances sperm motility and life span.
Answer to Question 2
ANS: B
Testosterone promotes the development of male reproductive organs and secondary sex characteristics. It causes bones and muscles to become longer and thicker (not thinner). Luteinizing hormone causes Leydig's cells in the testes to release androgens, including testosterone.