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
Endolymph in the inner ear - 
Select and explain. 
A. Is a filterate of blood serum, B. Is secreted by Stria vascularis, C. Is secreted by Basilar membrane, D. Is secreted by Hair cells
B: Is secreted by Stria vascularis
Answer: B: Is secreted by Stria vascularis 
Explanation: There are 2 main fluids in the inner ear.