Jolie Has Sickle-Cell Trait, a Temporary, Relatively Mild Form of Sickle-Cell

Multiple Choice

Jolie has sickle-cell trait, a temporary, relatively mild form of sickle-cell anemia, but does not have full-blown sickle-cell anemia. Her condition is most likely the result of

A) incomplete dominance between one allele for normal blood cells and one for sickle-shaped cells.
B) two recessive alleles for sickle-shaped cells.
C) a dominant sickle-shaped cell allele and a recessive normal blood cell allele.
D) two dominant alleles for normal blood cells.