Select the correct option decribing gonadotropin activity in a normal pregnant female:
A. high level of hCG stimulates the thickening of endoterium
B. high level of FSH and LH stimulate the thickening endometrium.
C. high level of FSH and LH facilitate implantation of the embryo
D. high level of hCG stimulates the synthsis of estrogen and progesterone.
