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': 'C shaped curve on tympanometry is seen in \nSelect and explain. \nA. Serous otitis media, B. Otosclerosis, C. TM perforation, D. Retracted tympanic membrane', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Type C tympanometry Maximum compliance occurs with negative pressure in excess of 100mm H2O Seen in retracted tympanic membrane and may show some fluid in middle ear. Ref: Dhingra 7e pg 27.', 'role': 'assistant'}]