Assume That a Researcher Is Studying Coat Color in Voles

Assume that a researcher is studying coat color in voles.Three strains of white vole have been isolated: milky, blanc, and weiss.White is a recessive trait in each strain.Homozygous white voles are obtained for each strain.Consider the following crosses: milky * blanc = all white progeny
Milky * weiss = all brown (wild-type vole color)
Blanc * weiss = all brown (wild-type vole color)
The conclusion most consistent with these results is

A) all three strains have mutations in the same gene.
B) all three strains have mutations in different genes.
C) milky and blanc have mutations on the same gene, weiss has a mutation in a different gene.
D) milky and weiss have mutations on the same gene, blanc has a mutation in a different gene.
E) weiss and blanc have mutations on the same gene, milky has a mutation in a different gene.