Please Help! Please only answer if you have correct answer 2. What, if anything, is the difference between semen and sperm?

A. Sperm and semen mean the same thing; they are synonyms of each other.

B. Sperm are the actual reproductive cells; semen is the combination of these cells and other secretions from the male reproductive tract.

C. Sperm help neutralize acid in the urethra and vagina; semen provides nutrient for sperm.

D. Sperm are immature reproductive cells; mature cells are called semen when they leave the epididymis.