This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Protein Synthesis Inhibitors, Subject name: Pharmacology
[{'content': 'Which of the following drugs acts by blocking RNA transcription? \nSelect and explain. \nA. Rifampicin, B. Streptomycin, C. Isoniazid, D. Chloramphenicol', 'role': 'user'}, {'content': 'Answer: A \nExplanation: DRUG MECHANISM Rifampicin Inhibit transcription of RNA Isoniazid Act on mycobacterial membrane Streptomycin Inhibit protein synthesis Chloramphenicol Inhibit protein synthesis', 'role': 'assistant'}]