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': 'Which one of the following is the contraceptive method of choice for a commercial sex worker : \nSelect and explain. \nA. OC pills, B. IUCD, C. Tubectomy, D. Barrier method', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Barrier method', 'role': 'assistant'}]