It has been found that a carrier is better able to survive diseases with severe diarrhea. What would happen to the frequency of the "c" if there was an epidemic of cholera or other type of diarrhea producing disease?

'c' would increase because of heterozygote advantage.

Explanation:

When someone has two different alleles of a gene then we say that the person is an heterozygote or the term used is known as heterozygote or heterozygous. The carrier is represented as Cc. When we say that someone has an heterozygote advantage we mean that the person's disease single allele does not cause such disease in other words we say that the person's heterozygous genotype is much more okay than recessive or dominant homozygous.