Birth Control Pills Contain a Combination of Estrogen and Progesterone

Multiple Choice

Birth control pills contain a combination of estrogen and progesterone.How would this prevent pregnancy?

A) It would prevent sperm from reaching the egg.
B) It would cause the embryo to die.
C) It would prevent implantation on the uterine wall.
D) If would act as a spermicide,killing sperm.
E) It would prevent ovulation.