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 does not affect the metabolism of Theophylline? \nSelect and explain. \nA. Erythromycin, B. Smoking, C. Cimetidine, D. Steroids', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Steroids does not affect metabolism of theophylline. Smoking is found to increase clearence of theophylline. Drugs increasing the clearence of theophylline are rifampicin, phenobarbitone and ethanol. Drugs inhibiting the clearence are cimetidine, erythromycin, ciprofloxacin, allopurinol and zileuton.', 'role': 'assistant'}]