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': 'Radical mastoidectomy includes all except \nSelect and explain. \nA. Closure of auditory tube, B. Ossicles removed, C. Cochlea removed, D. Exteriorisation of mastoid', 'role': 'user'}, {'content': 'Answer: C \nExplanation: It is an operation to eradicate disease of the middle ear and mastoid in which mastoid, middle ear, attic and the antrum are exteriorized into the external ear by removal of posterior meatal wall. All remnants of tympanic membrane, malleus, incus (not the stapes), chorda tympani and the mucoperiosteal lining are removed, and the opening of eustachian tube closed by packing a piece of muscle or cailage into the eustachian tube. Ref: Dhingra 7e pg 459.', 'role': 'assistant'}]