This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2019, Subject name: Gynaecology & Obstetrics
[{'content': 'A woman comes after 96 hours post coitus. Best contraceptive of choice is? \nSelect and explain. \nA. OCP, B. IUCD, C. Mifepristone, D. Progesterone only pills', 'role': 'user'}, {'content': 'Answer: B \nExplanation: IUCD: Can prevent implantation up till 5th day of unprotected inter-course Therefore, this is the most effective method for contraception', 'role': 'assistant'}]