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': 'Endolymph in the inner ear - \nSelect and explain. \nA. Is a filterate of blood serum, B. Is secreted by Stria vascularis, C. Is secreted by Basilar membrane, D. Is secreted by Hair cells', 'role': 'user'}, {'content': 'Answer: B \nExplanation: There are 2 main fluids in the inner ear.', 'role': 'assistant'}]