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': 'Maximum function of corpus luteum occurs : \nSelect and explain. \nA. At ovulation, B. Before ovulation, C. 3 days after ovulation, D. 9 days after ovulation', 'role': 'user'}, {'content': 'Answer: D \nExplanation: 9 days after ovulation', 'role': 'assistant'}]