A 30yrs old patient treated with features of acute meningoencephalitis in casualty

A 30yrs old patient treated with features of acute meningoencephalitis in casualty . His CSF on wet mount microscopy revealed motile unicellular microorganisms.The most likely organism is:

a.Naegleria fowleri

b.Acanthamoeba castellani

c.Entamoeba histolytica

d.Trypanosoma cruzi

ans:a.Naegleria fowleri