Coat color in mice is determined by genes at two loci. When black mice from a particular population of mate, they produce offspring in the following ratios: 9 black: 3 brown: 4 white. These results suggest that white coat color is expressed as a result of
a. Dominance
b. Incomplete dominance
c. Codominance
d. A sex-linked trait
e. Epistasis
Answer: E