Which of the Following Scenarios Describes an Example of Epistasis

Multiple Choice

Which of the following scenarios describes an example of epistasis?

A) Recessive genotypes for each of two genes (aabb) results in an albino corn snake.
B) In rabbits and many other mammals, one genotype (ee) prevents any fur color from developing.
C) In Drosophila (fruit flies) , white eyes can be due to an X-linked gene or to a combination of other genes.
D) In cacti, there are several genes for the type of spines.