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
RNA transcription is blocked by this ATT: 
Select and explain. 
A. Rifampicin, B. Streptomycin, C. Chloroamphenicol, D. INH
A: Rifampicin
Answer: A: Rifampicin 
Explanation: 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.