This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2019, Subject name: Pharmacology
[{'content': 'Mechanism of resistance of tetracyclines is due to? \nSelect and explain. \nA. Drug efflux mechanism, B. Development of inactivating enzymes, C. DNA methylation, D. Cell wall alteration', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Mechanism of Resistance Examples Enzymatic breakdown A: Aminoglycosides B: Beta lactams C: Chloramphenicol Decreased permeability Aminoglycosides Efflux pumps Tetracyclines Altered metabolic pathway Sulfonamides Altered target MRSA Vancomycin, Fluoroquinolones', 'role': 'assistant'}]