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': "Glycerol test is done in - \nSelect and explain. \nA. Otosclerosis, B. Lateral sinus thrombosis, C. Meniere's disease, D. None of the above", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Glycerol is a dehydrating agent. When given orally, it reduces endolymph pressure and causes improvement in hearing as evidenced by an improvement of 10 dB or 10% gain in discrimination score in Meniere’s disease patients.', 'role': 'assistant'}]