This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hearing Loss, Subject name: ENT
[{'content': 'Impedance audiometry is for the pathology of: \nSelect and explain. \nA. External ear, B. Middle ear, C. Mastoid air cell, D. Inner ear', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (b) Middle ear(Ref. Cummings, 6th ed., 2203)In impedance audiometry we do tympanometry which is a measure of the condition of the middle ear at the level of TM.', 'role': 'assistant'}]