In Horses,there Are Four Alleles at the a Locus

Multiple Choice

In horses,there are four alleles at the A locus.Arranged in dominance sequence,they are A (wild) ,a^b (bay) ,a^c (brown) ,a^d (black)
If you bred several bay mares whose sires were brown to a brown stallion whose sire was black,what are the genotypes of the parents; what type of offspring would be produced; and in what proportion?

A) a^aa^d x a^ca^d; 1/2 brown, 1/2 black
B) a^ba^c x a^ca^d; 1/2 bay, 1/2 brown
C) Aa^b x a^ca^d; 1/2 bay, 1/2 wild
D) Aa^b x a^ca^d; all wild
E) a^da^b x a^ca^d; all black