This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Reproductive physiology and hormones in females, Subject name: Gynaecology & Obstetrics
[{'content': 'Normal blood loss in menstruation is \nSelect and explain. \nA. 20-40ml, B. 40-80ml, C. 80-120ml, D. 120-150ml', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Normal blood loss during menstruation is 30-40ml Ref: Internet sources', 'role': 'assistant'}]