This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Non-pathogenic amoebae is/are - 
Select and explain. 
A. E. histolytica, B. E.coli, C. Acanthanmoeba, D. All
B: E.coli
Answer: B: E.coli 
Explanation: Ans. is 'b' i.e., E. coli Non-pathogenic amaebae are E.hamanni, E.coli, E.polecki, Endolimax nana, lodamoeba botschlii, and Dientamoeba fragilis.