In Purple People Eaters, Purple Is Dominant to White

Multiple Choice

In purple people eaters, purple is dominant to white. A true-breeding white mutant is mated with a different true-breeding white mutant. All of the F₁ are purple. When the purple F₁ offspring mate with each other, their offspring occur in the ratio of 9 purple : 7 white. Which phenomenon explains the purple F₁ offspring?

A) recessive epistasis
B) dominant epistasis
C) complementation
D) mutation
E) suppression