Design diagnostic test to distinguish mutant allele | Quick Homework Help

I want to design a diagnostic test to distinguish a mutant allele from a wild type allele, as in the two allele depicted below. I have the choice of using two restriction enzymes (A and B) with target sites marked by the placement of A and B on th etwo alleles below. The resultant fragments friom the digestion of the two alleles are indicated below in parantheses. Suppose you design a PCR test for detecting one or the other allele using a single set of primers. For your test, which of the following represent all valid choices of restriction enzymes to detect a difference between teh two alleles?

___(100)__A__(300)__A__(100)___ WT
_______(500)____B____(500)_____ Mutant
A. only A
B. only B
C. neither A nor B
D. A and B
E, you can only use A and B together