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': 'All contribute to postpaum hemorrhage, except: \nSelect and explain. \nA. Epidural analgesia, B. Small for date, C. Prolonged labour, D. High multiparity', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Small for date', 'role': 'assistant'}]