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': "Gelle's test is done in? \nSelect and explain. \nA. Otosclerosis, B. Serous otitis media, C. Senile deafness, D. Traumatic deafness", 'role': 'user'}, {'content': "Answer: A \nExplanation: Gelle's test is a test of bone conduction and examines the effect of increased air pressure in the ear canal on hearing. Gelle's test is positive in normal person and in those with sensorineural hearing loss. It is negative when ossicular chain is fixed or disconnected. It was a popular test to find out stapes fixation in otosclerosis but has now been superceded by tympanometry.", 'role': 'assistant'}]