Kevin has decided to start breeding bulldogs, but he only wants to breed small white dogs. He goes to different breeders to purchase the dogs he will use to start his line. He buys the smallest white female he can find and the smallest white male he can find. When those dogs have their first set of puppies, he keeps only the smallest white puppies from the litter, selling all others, to continue his line. Kevin is engaging in
A) selective breeding.
B) molecular genetics.
C) collateral sprouting.
D) neurogenesis.