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': 'Otospongiosis causes - \nSelect and explain. \nA. U/L conductive deafness, B. B/L conductive deafness, C. U/L sensorineural deafness, D. B/L sensorineural deafness', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]