This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'Which of the following drug is an inhibitor of cytochrome p450 enzyme \nSelect and explain. \nA. Ketoconazole, B. Rifampecin, C. Phenytoin, D. Phenobarbitone', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ketoconazole is a powerful microsomal enzyme inhibitor where as rifampicin,phenobarbitone and Phenytoin are enzyme inducers Refer KDT 7-e p26', 'role': 'assistant'}]