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': 'Which of the following drug can lead to increased level of Theophylline \nSelect and explain. \nA. Rifampicin, B. Phenobarbitone, C. Cimetidine, D. Phenytoin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Cimetidine is an enzyme inhibitor which can increase theophylline levels and lead to toxicity.', 'role': 'assistant'}]