Question

thickening of the endometrium is controlled by:
progesterone
lh
fsh
estrogen

Explanation:

In the menstrual cycle, estrogen is responsible for the thickening of the endometrium (the uterine lining). Progesterone maintains the endometrium, while LH (Luteinizing Hormone) and FSH (Follicle - Stimulating Hormone) have other roles in the cycle like triggering ovulation and follicle development respectively.

Answer:

D. Estrogen (assuming the options are labeled A to D with A: Progesterone, B: LH, C: FSH, D: Estrogen)