All of the following form the floor of third ventricle, except: (A) Infundibulum, (B) Occulomotor nerve, (C) Mammillary body, (D) Optic chiasma
Answer is B. Floor of third ventricle is formed from before backward by :Optic chiasmaTuber cinerum & infundibulumMammillary bodiesPosterior perforated substanceTegmentum of midbrain(Ref: Vishram Singh textbook of clinical neuroanatomy second edition pg 137)