5. What is unusual about peanuts?
a. After fertilization, a peg elongates and grows downward and into the soil to a depth of 1 to 2 inches where pods form.
b. Peanuts are self-pollinated, unlike nearly all the other oil crops.
c. Peanuts are the only angiosperms under cultivation that undergo a single fertilization rather than two.
d. The plant roots send up floral stalks which are fertilized and retract into the ground for seed development.