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': 'Following drugs are cell wall synthesis inhibitors except? \nSelect and explain. \nA. Colistin, B. Fosfomycin, C. Bacitracin, D. Cycloserine', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Colistin", 'role': 'assistant'}]