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
A child is brought to the emergency depament with signs of meningeal irritation. She had suppurative otitis media in the last week. Infection of middle ear can spread to CNS through: 
Select and explain. 
A. Venous plexus, B. Cochlear aqueduct, C. Cochlear nerve sheath, D. Bloodstream
B: Cochlear aqueduct
Answer: B: Cochlear aqueduct 
Explanation: In the setting of middle ear infection, bacterial infection can invade through the round window causing acute suppurative labyrinthitis. From the labyrinth, bacteria gain access to the cochlear aqueduct, forming a conduit between the perilymph and the cerebrospinal fluid (CSF) resulting in meningeal infiltration.