This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Antibiotics, Subject name: Pharmacology
[{'content': 'Which of the following drug is useful in the prophylaxis of meningococcal meningitis? \nSelect and explain. \nA. Minocycline, B. Doxycycline, C. Cephalexin, D. Rifabutin', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Minocycline is used in acne and for prophylaxis of meningococcal meningitis.Ref: HL Sharma 3rd ed Pg:', 'role': 'assistant'}]