An Avid Marathon Runner in His Early Thirties and His

An avid marathon runner in his early thirties and his wife have been trying unsuccessfully for the last year to get pregnant. What advice would a doctor be most likely to give them?

A) Don't worry, only about 70% of couples become pregnant in the first year of trying.
B) Consider a sperm donor, as male fertility declines rapidly after age 30.
C) Try to boost sperm count by exercising less.
D) Try to boost sperm count by exercising more.
E) Try to increase sperm motility by wearing snug-fitting clothing to keep the testes warm.