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
Which of the following drugs is most effective against an organism producing aminoglycoside inactivating enzymes ? 
Select and explain. 
A. Tobramycin, B. Gentamicin, C. Amikacin, D. Streptomycin
C: Amikacin
Answer: C: Amikacin 
Explanation: None