A cross between true-breeding green-podded pea plants and true-breeding yellow-podded pea plants produces only green-podded plants. When the F1 generation is allowed to self-pollinate, the F2 generation consists of
a. only green-podded plants
b. only yellow-podded plants
c. about three-quarters yellow-podded plants and one-quarter green-podded plants
d. about three-quarters green-podded plants and one-quarter yellow-podded plants
Answer: D