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': 'All of the following are risk factors for renal toxicity caused by aminoglycosides EXCEPT : \nSelect and explain. \nA. Elderly patient, B. Hypokalemia, C. Simultaneous use of penicillin, D. Aminoglycoside administration in recent past', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]