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 peak level of chorionic gonadotropin in normal pregnancy occurs at : \nSelect and explain. \nA. 30 -- 40 days, B. 60 -- 70 days, C. 10 -- 20 days, D. 100 -- 110 days', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 60 -- 70 days', 'role': 'assistant'}]