Suppose that within the dog population of u.s. bull terriers the prevalence of pure white bull terriers (rr) increased within the breed so significantly that the frequency of the white allele (r) jumped by 20% during the 25-year period from 1985 to 2010. assuming the major factor increasing the occurrence of the white (r) allele was that breeders and kennels outside the united states imported large numbers of black bull terriers from the u.s. during this period, which principle applies

During the period mentioned in the question, the Hardy-Wienberg principle is applied.

According to the Hardy-Wienberg principle, five IDEAL conditions must be maintained:

1. Random Mating
2. No Mutations
3. Isolation from Other Populations
4. Large Production Size
5. No Natural Selection

Hardy-Wienberg principle is an equation that explains how genes are inherited in a population, based on the allele frequency in the population or gene pool.

It's not natural selection

Just took the test and got it wrong.

C. warm land

Explanation: