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: Pharmacology
[{'content': 'Dose of levonorgestrol for contraception is \nSelect and explain. \nA. 0.75 mg single dose, B. 1.5 mg single dose, C. 1.5 mg double dose, D. 7.5 mg single dose', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Levonorgestrol should be given as 0.75 mg 2 doses 12 hours apart or 1.5 mg single dose within 72 hours of unprotected sexual intercourse.', 'role': 'assistant'}]