This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti Microbial, Subject name: Pharmacology
[{'content': 'RNA transcription is blocked by this ATT: \nSelect and explain. \nA. Rifampicin, B. Streptomycin, C. Chloroamphenicol, D. INH', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ref: 7th ed. Pg. 768MOA OF IMPORTANT ATT* Streptomycin- inhibit protein synthesis* Chloroamphenicol- inhibit protein synthesis by inhibiting transpeptidation* Rifampicin- inhibit DNA dependent RNA synthesis by inhibiting RNA polymerase* INH & Pyrazinamide: inhibits mycolic acid, a component of mycobacterial cell wall* Ethambutol: Inhibit incorporation of mycolic acid into bacterial cell wall by inhibiting arabinosyl transferase, thus weakening the wall.', 'role': 'assistant'}]