The corpus luteum

A) degenerates into the corpus albicans if pregnancy does not occur.
B) is absolutely necessary during the first three months of pregnancy.
C) produces mostly progesterone, but also some estrogen.
D) All of the choices are correct.

The corpus luteum, formed from the remnants of the follicle after ovulation, plays a crucial role in the menstrual cycle and early pregnancy. If pregnancy does not occur, it degenerates into the corpus albicans. During the first three months of pregnancy, it is essential for maintaining the uterine lining, producing significant amounts of progesterone and some estrogen to support pregnancy until the placenta takes over hormone production.