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
All of the following are risk factors for renal toxicity caused by aminoglycosides EXCEPT : 
Select and explain. 
A. Elderly patient, B. Hypokalemia, C. Simultaneous use of penicillin, D. Aminoglycoside administration in recent past
C: Simultaneous use of penicillin
Answer: C: Simultaneous use of penicillin 
Explanation: None