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': 'Post head injury, the patient had conductive deafness and on examination, tympanic membrane was normal and mobile with increased compliance on impedance. Likely diagnosis is: \nSelect and explain. \nA. Distortion of ossicular chain, B. Hemotympanum, C. Tympanosclerosis, D. Otosclerosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (a) Distortion of ossicular chain(Ref Cummings, 6th ed., 2055)Intact TM with increased compliance on impedance suggests distortion of ossicular chain.Hemotympanum is a possibility following head injury leading to conductive deafness but here TM compliance will be reduced.Tympanosclerosis and otosclerosis do not follow head injury and Tympanometry shows reduced compliance.', 'role': 'assistant'}]