This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General obstetrics, Subject name: Gynaecology & Obstetrics
[{'content': 'Puerperium is the period \nSelect and explain. \nA. 6wks following delivery, B. 3wks following delivery, C. 2wks following delivery, D. 1wk following delivery', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Purperium begins as soon as the placenta is expelled and lasts for approximately 6wks when the uterus becomes regressed almost to the nonpregnant size.', 'role': 'assistant'}]