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: Anatomy
Organ of coi is situated in ? 
Select and explain. 
A. Basilar membrane, B. Utricle, C. Saccule, D. None of the above
A: Basilar membrane
Answer: A: Basilar membrane 
Explanation: Scala media (cochlear duct or membranous labyrinth) has 3 walls : -i) The basilar membrane, which suppos the organ of coi.ii) The Reissner's membrane which separates it from the scala vestibuli.iii) The stria vascularis which contains vascular epithelium and is concerned with secretion of endolymph.