What could be the possible result of founder effect on genetic variation? a. decrease in genetic variation b. increase in genetic variation c. no change in genetic variation

The answer is A. Decrease in genetic variation

A founder effect is a result of a geographical separation of a few individuals from the original population. Those few founding individuals will form a new population so they are founders. In this new population, there will be present alleles of the few founding individuals. However, those few founding individuals do not represent a whole genetic variation of the old population, but only some part of it.
Imagine a population of fish in which there are yellow, green, blue, and red colored fish. In the population, there is a genetic variation. But, if a few green-colored and red-colored fish geographically separate from the population and form a new population, in the new population there will be decreased genetic variation (because there are only green and red fish compared to the old population where are fish in 4 different colors).