Non-pathogenic amoebae is/are -: (A) E. histolytica, (B) E.coli, (C) Acanthanmoeba, (D) All
Answer is B. Ans. is 'b' i.e., E. coli Non-pathogenic amaebae are E.hamanni, E.coli, E.polecki, Endolimax nana, lodamoeba botschlii, and Dientamoeba fragilis.