The activity of predators has caused their prey to evolve a variety of protective characteristics. How were the prey able to acquire these new features?

A)The prey selectively bred in order to increase the frequency of protective traits in their population.
B)The prey underwent a population explosion that allowed them to outnumber their predators and thus develop new protective features.
C)The prey organisms mated with other species in order to acquire new protective traits.
D)Natural selection acted on genetic variability already present in the prey population.