A rancher wants to investigate the use of artificial selection in his cattle herd. Which of these options is an example of artificial selection?
A) Breed a cow that produces large quantities of milk with a bull that comes from a line of cattle with long lifespans.
B) Trace the family tree of a chicken that lays many eggs back through several generations.
C) Separate a population of rabbits and monitor any trait changes over the next few generations.
D) Choose one individual in a population of sheep to favor with food and shelter and see if it mates more.