Answer the following question given this paragraph: 

Since natural selection acts on the phenotype, if an allele causes death in a homozygous individual, aa , for example, it will not cause death in a heterozygous Aa individual. These heterozygous Aa individuals will then act as carriers of the a allele, meaning that the a allele could be passed down to offspring. People who are carriers do not express the recessive phenotype, as they have a dominant allele. This allele is said to be kept in the population's gene pool. The gene pool is the complete set of genes and alleles within a population.


Q: What is the term for the complete set of genes and alleles within a population?

 Choices:

- the ancestral pool

- the chromosomal pool

- the biodiversity pool

- the gene pool

A:
the gene pool
