In shorthorn cattle genes for red \[({{r}_{1}}),\] and white \[({{r}_{2}})\] coat colour occur. Crosses between red \[({{r}_{1}}{{r}_{2}})\] and white \[({{r}_{2}}{{r}_{2}})\] produced \[({{r}_{1}}{{r}_{2}})\] roan. This is an example of [BHU 2003]

• A. Complementary genes
• B. Epistasis
• C. Codominance
• D. Incomplete dominance