Which Statement About Gene Cascades Is False

Which statement about gene cascades is false?

A) Alterations in a single gene within a gene cascade can affect an animal's behavior and fitness.
B) Gene cascades create opportunities for simple genetic changes to alter complex behavior.
C) Genes within cascades can influence several other genes.
D) A gene cascade controls sexual differentiation in fruit flies.
E) The fru gene is not part of the genetic cascade that controls sexual differentiation in fruit flies.