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 except one is recommended for use in emergency contraception \nSelect and explain. \nA. Combined oral contraceptives, B. Progestin only regimens, C. Selective oestrogen receptor modulators, D. Antiprogestins', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Selective progestin receptor modulators are used as emergency contraceptive.', 'role': 'assistant'}]