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
[{'content': 'Infection of CNS spreads to inner ear through \nSelect and explain. \nA. Cochlear aqueduct, B. Endolymphatic sac, C. Vestibular aqueduct, D. Hyle fissure', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 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.', 'role': 'assistant'}]