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 risk factors of acute pelvic inflammatory disease (PID) are the following except: \nSelect and explain. \nA. Menstruating teenagers who have multiple sex partners, B. IUD users, C. Women with monogamous partner who had vasectomy, D. Previous history of acute PID', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]