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': 'A young female Shagun comes to you in the gynecology OPD and gives the history that she had intercourse with her boyfriend 5 hours back. Select the drug that can act as a single dose postcoital contraceptive for her: \nSelect and explain. \nA. Clomiphene citrate, B. Mifepristone, C. Danazol, D. Medroxyprogesterone acetate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]