Biology

The correct answer is: D.Genetic Drift.

Explanation:

The scenario described involves a small group of deer moving into a new area where no deer had been before. This is an example of the founder effect, a form of genetic drift. When a small group of individuals starts a new population, the genetic makeup of that population is influenced by the alleles in the founding individuals, which may not represent the full genetic diversity of the original population. Over time, genetic drift can lead to changes in allele frequencies in the new population due to random chance.

The other options are incorrect for the following reasons: