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': 'Which of the following drug acts at 50s ribosome: \nSelect and explain. \nA. Stremptomycin, B. Tetracycline, C. Quinpristin, D. Demeclocycline', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ref: Sharma & Sharma 3rd ed. P 702Protein synthesis inhibitor drugs acting at 30s and 50s ribosomal unitDrugs acting by inhibiting 30s ribosomeAminoglycoside (Streptomycin,Gentamicin, Tobramycin, Kanamycin, Amikacin)Tetracycline (Minocycline, Demeclocyclin, Doxycycline)Drugs acting by inhibiting 50s ribosomeStreptogramins (Quinpristin & Dalfopristin)Erythromycin (macrolides)Lincosamides (Clindamycin)LinezolidKetolides (Telithromycin, Cethromycin) ChloramphenicolMn: Buy AT 30, SELL Karo China in 50', 'role': 'assistant'}]