This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Otosclerosis, Subject name: ENT
[{'content': "In noise induced hearing loss , audiogram shows a Boiler's notch at ? \nSelect and explain. \nA. 1000 Hz, B. 2000 Hz, C. 3000 Hz, D. 4000 Hz", 'role': 'user'}, {'content': "Answer: D \nExplanation: Noise induced hearing loss Boiler notch at 4000 HZ Max seen at 3000 - 6000 HZ Sterocilia of outer hair cells are 1st to be affected . Carha's notch - dip is present at 2000 HZ .(seen in otosclerosis)", 'role': 'assistant'}]