Genetics: multiple alleles??

I'm guessing the answer is B. Several different genes control fur color. A certain gene codes for proteins that create the pigment in the fur, which is melanin. Another gene codes for proteins that deposit the pigments into the fur. So, we know that at least 2 genes control fur color: if one of these genes was recessive, the fur would be white. If they were dominant, the phenotype would show a certain color.