Answer:
Option C, Genetic drift
Explanation:
Separation of a part of a population from the main population group there by causing reduction of allele frequency is known as founder effect and founder effect is a form of genetic drift.
For example -
A small island has a a species of plant that has red and white color flowers. Some how the plants producing white flowers got removed from the island and hence plants now only produce red flower. This incidents must have reduced the allele frequencies of both red and white flower.
Thus, option C is correct
