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: Ophthalmology
[{'content': 'Ophthalmoscopic sign pathognomonic of optic nerve sheath meningioma is: \nSelect and explain. \nA. Papilloedema, B. Optic atrophy, C. Opticociliary shunt, D. All of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. Opticociliary shunt', 'role': 'assistant'}]