How does natural selection favor heterozygous individuals for the sickle cell trait in areas with high malaria prevalence?

• A. They have severe sickle cell disease and no resistance to malaria.
• B. They have no sickle cell disease and are fully susceptible to malaria.
• C. They have resistance to malaria and severe sickle cell disease.
• D. They have resistance to malaria without severe sickle cell disease.

Answer: (D)