Tom has always wanted to be a father but has not yet found an acceptable partner. He is now 35 years old, healthy, and beginning to be concerned about how much longer he will remain fertile. When he asks his doctor about this, his doctor tells him that he will probably be capable of fathering a child

a. until he is about 45 years old.
b. until he is about 65 years old.
c. until he is about 85 years old.
d. for the rest of his life.

d