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': "Dunda's grant apparatus used in: \nSelect and explain. \nA. Cold air caloric test, B. Fitzgerald Hallpike's test, C. Bithermal caloric test, D. Rinne test", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Cold caloric test--employs Dundas Grant tube, which is a coiled tube wrapped in cloth. The air in the tube is cooled by pouring ethyl chloride and then blown into the ear.', 'role': 'assistant'}]