Use the Following to Answer Questions

Multiple Choice

Use the following to answer questions
The diagram below illustrates the normal expression of three different groups of genes (A, B, and C) within four different whorls of a developing flower. Normally, whorl 1 produces sepals, whorl 2 produces petals, whorl 3 produces stamens, and whorl 4 produces carpels. Furthermore, expression of class A genes inhibits class C genes, and expression of class C inhibits class A.
-What kind of mutation would produce sepals in all four whorls?

A) defective in A
B) defective in B
C) defective in C
D) defective in A and B
E) defective in B and C