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': 'Dose of which of the following antibiotic does not require alteration in renal failure ? \nSelect and explain. \nA. Vancomycin, B. Ethambutol, C. Erythromycin, D. Metronidazole', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]