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
Following drugs are cell wall synthesis inhibitors except? 
Select and explain. 
A. Colistin, B. Fosfomycin, C. Bacitracin, D. Cycloserine
A: Colistin
Answer: A: Colistin 
Explanation: Ans. is 'a' i.e., Colistin