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': 'Impedance audiometry is for pathology of-, \nSelect and explain. \nA. External ear, B. Middle ear, C. Mastoid air cell, D. Inner ear', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Impedence autiometry is used to find the health or diseased status of middle ear.', 'role': 'assistant'}]