This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Female Reproductive System, Subject name: Physiology
[{'content': 'True about estrogen: \nSelect and explain. \nA. Inhibits osteoblast, B. Decreases expression of LDL receptors, C. C19 steroid, D. Estradiol is most potent among estradiol, estratriol and estrone', 'role': 'user'}, {'content': 'Answer: D \nExplanation: All C18 steroids, including estrone, estradiol, and estriol, are commonly referred to as estrogens. Estriol is a weak estrogen; it is an oxidative product derived from both estradiol and estrone, with the conversion occurring mainly in the liver. The estrogenic potency of b-estradiol is 12 times that of estrone and 80 times that of estriol Estradiol-17b is also one of the most potent regulators of osteoblast and osteoclast function. Estrogen promotes survival of osteoblasts and apoptosis of osteoclasts, thereby oring bone formation over resorption.', 'role': 'assistant'}]