This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ear, Subject name: ENT
Infection of CNS spreads to inner ear through 
Select and explain. 
A. Cochlear aqueduct, B. Endolymphatic sac, C. Vestibular aqueduct, D. Hyle fissure
A: Cochlear aqueduct
Answer: A: Cochlear aqueduct 
Explanation: The scala tympani is closed by a secondary tympanic membrane. It is also connected with subarachnoid space through aqueduct of cochlea Reference: Dhingra 6th edition.