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: Social & Preventive Medicine
[{'content': 'For emergency contraception IUD must be inserted \nSelect and explain. \nA. Immediately, B. Within 5 days of coitus, C. Within 7 days of coitus, D. IUD is not used as emergency contraception', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]