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
[{'content': 'Mechanism of action of vancomycin is : \nSelect and explain. \nA. Inhibition of cell wall synthesis, B. Inhibition of protein synthesis, C. Leakage from cell membrane, D. Inhibition of DNA gyrase', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]