This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy, Subject name: Pharmacology
Bacitracin acts on 
Select and explain. 
A. Cell wall, B. Cell membrane, C. Nucleic acid, D. Ribosome
A: Cell wall
Answer: A: Cell wall 
Explanation: Ref Katzung 10/e p 741 Bacitracin acts by inhibiting the synthesis of cell wall Other polypeptide antibiotics like Polymyxin B, colistin and tyrothricin act by affecting membranes