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 drug is not effective by oral route? \nSelect and explain. \nA. Erythromycin, B. Ciprofloxacin, C. Streptomycin, D. Albendazole', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Aminoglycosides like streptomycin are not effective orally because these are polar molecules and are not absorbed from GIT', 'role': 'assistant'}]