Non-pathogenic amoebae is/are -
Ans. is 'b' i.e., E. coli Non-pathogenic amaebae are E.hamanni, E.coli, E.polecki, Endolimax nana, lodamoeba botschlii, and Dientamoeba fragilis.
E. histolytica
E.coli
Acanthanmoeba
All