Although each of the following has a better chance of influencing ...

[Garrulous]

Although each of the following has a better chance of influencing gene frequencies in small populations than in large populations, which one most consistently requires a small population as a precondition for its occurrence?
A) mutation
B) nonrandom mating
C) genetic drift
D) natural selection
E) gene flow

[Hawke]

Hello

C is the answer.