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: Medicine
Drug of choice in methicillin-resistant Staphylococcus aureus 
Select and explain. 
A. Ceftriaxone, B. Ceftazidime, C. Ampicillin, D. Vancomycin
D: Vancomycin
Answer: D: Vancomycin 
Explanation: None