People Homozygous for the Sickle-Cell Anemia Allele Develop a Life

Multiple Choice

People homozygous for the sickle-cell anemia allele develop a life threatening disease, while those homozygous for the normal allele are at the highest risk of dying from malaria.Carriers have some resistance to malaria, but do not develop sickle cell anemia.This is an example of ____

A) founder effect.
B) genetic bottleneck.
C) heterozygosity.
D) heterozygote advantage.