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: ENT
Infection of CNS spreads to the inner ear through which of the structures? 
Select and explain. 
A. Cochlear Aqueduct, B. Endolymphatic sac, C. Vestibular Aqueduct, D. Hyle's fissure
A: Cochlear Aqueduct
Answer: A: Cochlear Aqueduct 
Explanation: Cochlear aqueduct: connects scala tympani to CSF The labyrinth maintains connections with the central nervous system (CNS) and subarachnoid space by way of the internal auditory canal and cochlear aqueduct. Bacteria may gain access to the membranous labyrinth by these pathways or through congenital or acquired defects of the bony labyrinth.