Preven, the first type of morning-after pill, could be taken over the period of one to three days after unprotected sex because
A) sperm do not reach the egg until the third day after intercourse.
B) the release of FSH and LH is at a relatively stable concentration until the third day after intercourse.
C) implantation of the embryo does not take place until around the third day after fertilization.
D) the placenta begins production of HCG on the third day after fertilization.
E) the corpus luteum does not develop until the third day.

Question

Quizplus · Accepted Answer

Preven, the morning-after pill, works by preventing implantation of the embryo in the uterus. Implantation usually occurs around the third day after fertilization. Therefore, Preven can be taken over the period of one to three days after unprotected sex to prevent implantation and ultimately prevent pregnancy.

Preven, the First Type of Morning-After Pill, Could Be Taken