This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti-Leprotic, Subject name: Pharmacology
[{'content': 'Fastest acting drug in leprosy is : \nSelect and explain. \nA. Rifampicin, B. Dapsone, C. Clofazimine, D. Ethionamide', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. is \'a\' Rifampicin. Harrison says "Rifampicin is the most active agent for leprosy"', 'role': 'assistant'}]