In regions of the world where malaria occurs, the sickle-cell allele is found at a higher frequency. What is the explanation for this?
- ABoth diseases are caused by the same allele.
- BHeterozygous individuals with the sickle-cell allele are less likely to have malaria.
- CHeterozygous individuals with the sickle-cell allele are more likely to have malaria.
- DThese are parts of the world with many diseases.