Answer: The correct answer is-
Genetic drift tends to occur in populations that are small.
Genetic drift can be described as an evolutionary mechanism, according to which frequency of gene variant ( that is allele frequency) changes over generation within a population due to some random/ chance events.
It has a pronounced impact on population with small size.
This is because in small population, infrequently-occurring gene variants have a larger probability of getting lost.
As it is initiated,it will continue until the gene variant is either lost or is the only allele left at the gene locus within a population.
This will result in the decrease of the genetic diversity of population.