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
Elaboration of inactivating enzymes are the important mechanism of drug resistance among all of these antibiotics EXCEPT : 
Select and explain. 
A. Quinolones, B. Penicillin, C. Chloramphenicol, D. Aminoglycosides
A: Quinolones
Answer: A: Quinolones 
Explanation: Resistance to fluoroquinolones is mediated by mutation in DNA gyrase.