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: Microbiology
[{'content': 'Methicillin resistance in Staph. aureus is due to: \nSelect and explain. \nA. 13-lactamase, B. MECA gene, C. AMPC gene, D. Porin develop', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. is. b. MECA gene', 'role': 'assistant'}]