The total of all the alleles in a population is called a:

Explanation

The total set of gene copies for all genes in a population is referred to as its gene pool. (A: Genetic drift) is the change in the frequency of an existing gene variant in a population due to random sampling of organisms. (B: Genotype) is an organism's set of heritable genes that can be passed down from parents to offspring. (D: Gene mutation) is a permanent alteration in the DNA sequence that makes up a gene.