This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Pharmacology
Which of the following drugs is most effective against an organism producing aminoglycoside inactivating enzymes? 
Select and explain. 
A. Amikacin, B. Streptomycin, C. Gentamicin, D. Tobramycin
A: Amikacin
Answer: A: Amikacin 
Explanation: (Ref: KDT 6/e p724) Amikacin is most resistant to aminoglycoside inactivating enzymes. Aminoglycosides are not effective against anaerobes.