This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
[{'content': 'The production of cervical mucus is stimulated by \nSelect and explain. \nA. Progesterone, B. Pregnenolone, C. Estriol, D. Estradiol', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Cervical mucus is a glycoprotein gel that expand and contract in response to cyclic changes in the steroid hormone environment across the menstrual cycle to facilitate or inhibit the passage of sperm\n\nEstrogen\xa0stimulates cervical mucus production, and as levels rise during the follicular phase, mucus becomes more abundant and watery, less cellular, and more easily penetrated by sperm\nProgesterone\xa0inhibits cervical mucus production and renders it opaque, viscid, and impenetrable', 'role': 'assistant'}]