Bateson and Punnett mated purple sweetpeas with white sweetpeas.F1 hybrids were all purple in color.When the hybrids were mated a ratio of 9 purple :7 white were observed in the F2 generation.Which of the following could best explain this observation?
A) Incomplete penetrance B) Lethal alleles C) Epistasis D) Codominance E) Incomplete dominance