This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: general microbiology, Subject name: Microbiology
[{'content': 'Which of the following antibiotic acts by inhibition of cytoplasmic membrane function? \nSelect and explain. \nA. Penicillin, B. Polymycin, C. Streptomycin, D. Novobiocin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Polymyxin bacitracin acts by inhibiting cell membrane or plasma membrane Not cell wall Penicillin -cell wall,streptomycin-protein synthesis inhibition Ref: CP Baveja 4th ed Pg:625', 'role': 'assistant'}]