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
[{'content': "Infection of CNS spreads to the inner ear through \nSelect and explain. \nA. Cochlear aqueduct, B. Endolymphatic sac, C. Vestibular aqueduct, D. Hyrtl's fissure", 'role': 'user'}, {'content': 'Answer: A \nExplanation: The scale tympani is closed by a secondary tympanic membrane.\xa0It is also connected\xa0with subarachnoid space through aqueduct of the cochlea', 'role': 'assistant'}]