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
Which of the following drug is not effective by oral route? 
Select and explain. 
A. Erythromycin, B. Ciprofloxacin, C. Streptomycin, D. Albendazole
C: Streptomycin
Answer: C: Streptomycin 
Explanation: Aminoglycosides like streptomycin are not effective orally because these are polar molecules and are not absorbed from GIT