Zoos Often Loan Animals to Other Zoos for Breeding Purposes

Zoos often loan animals to other zoos for breeding purposes. From an evolutionary standpoint, what is the benefit?

A) It creates a bottleneck effect.
B) New animals increase zoo revenues.
C) It increases the rate of random mutations.
D) It increases the genetic diversity of the zooʹs population.
E) It increases the effects of natural selection on the population.