The correct option is B Sewall Wright
Genetic drift is the change in the gene frequency in a population by a chance event. This concept was introduced by Sewall Wright. The effects of genetic drift are more profound in a smaller population. A smaller population already has a reduced gene pool. Loss of alleles from a smaller population will more profoundly be noticeable within a less time duration.
This leads to a change in the allele frequencies randomly.
Godfrey Harold Hardy, a mathematician and Wilhelm Weinberg, a physician came up with a mathematical equation describing genetic equilibrium in a population known as Hardy-Weinberg law.
Hugo De Vries proposed the mutation theory which states that new species are formed due to single step large mutation called saltation.