A Heterozygous, but Phenotypically Wild- Type Fruit Fly Gray Body

A heterozygous, but phenotypically wild- type fruit fly gray body colour and normal wings) was mated to a black fly with vestigial wings. The offspring had the following phenotypic distribution: wild type, 720;
Black- vestigial, 780; black- normal, 280; gray- vestigial, 220. What conclusion is likely from these results?

A) Epistasis has modified a 9:3:3:1 ratio.
B) The black and vestigial loci are linked.
C) The black and vestigial loci are allelic.
D) The black and vestigial loci assort independently from each other.