Comparisons of Sickle-Cell Anemia Among the African-American Population and the Bamba

Comparisons of sickle-cell anemia among the African-American population and the Bamba tribe in Africa suggest that

A) the incidence of sickle-cell anemia is equivalent among the two populations.
B) the sickle-cell gene offers some resistance to malaria.
C) sickle-cell anemia is caused by parasites that carry malaria so it is more common on the continent of Africa.
D) the symptoms of sickle-cell anemia are less severe among the Bamba.