. Sickle cell anemia is an example of
D: Incomplete dominance.
A:Epistasis - Epistasis is a non-allelic gene interaction in which one gene masks or modifies the expression of another, preventing the latter from fully expressing.
B:Codominance - The expression of both parents' phenotypes in the progeny is referred to as codominance. The ABO blood group type has a high degree of codominance.
C:Pleiotropy - Pleiotropy refers to a gene's ability to exhibit many phenotypic effects. Pleiotropy is the term for this phenomenon, and the gene responsible for it is called Pleiotropic gene. Pleiotropy can be seen in sickle cell anaemia.
D:Incomplete dominance - Incomplete dominance occurs when none of a gene's factors are dominant, and a heterozygous dominant individual's phenotype is a mix of dominant and recessive traits.
Hence, the correct answer is C, Pleiotropy.