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': 'When do progesterone levels rise to their highest point during the female hormonal cycle? \nSelect and explain. \nA. Between ovulation and the beginning of menstruation, B. Immediately before ovulation, C. When the blood concentration of LH is at its highest point, D. When 12 primary follicles are developing to the antral Stage', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The corpus luteum is the only source of progesterone production, except for minute quantities secreted from the follicle before ovulation. The corpus luteum is functional between ovulation and the beginning of menstruation, during which time the concentration of LH is suppressed below the level achieved during the preovulatory LH surge', 'role': 'assistant'}]