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': 'Bitherinal caloric test tests: \nSelect and explain. \nA. Anterior semicircular canal, B. Horizontal semicircular canal, C. Superior semicircular canal, D. Posterior semicircular canal', 'role': 'user'}, {'content': 'Answer: B \nExplanation: In Fitzgerald-Hallpike test/ bithermal caloric test, patient lies supine with head tilted 30deg forward so that horizontal canal is veical. Ears are irrigated for 40 seconds alternatively with water at 30degC and at 44deg C (70 below & above normal temperature) & observed for appearance of nystagmus till its end point', 'role': 'assistant'}]