Which of the following explains why the allele for sickle-cell disease remains at a relatively high level in the population?

People who carry one sickle-cell allele and one typical allele are more resistant to malaria than people without the sickle-cell allele. This survival advantage helps keep the allele relatively common in regions where malaria is widespread, even though inheriting two sickle-cell alleles can cause serious disease. The correct choice is that the allele confers protection from malaria to carriers.

AI-written and checked against the verified answer.