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': 'All are seen in papilloedema EXCEPT - \nSelect and explain. \nA. Hyperemia of disc, B. Sudden vision loss, C. Post - neuritic atrophy, D. Macular fan', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Vision loss occurs in long standing papilloedema (not in acute pappiloedema), and that occurs in less than 25% of patients.\nPost neuritic atrophy also occurs in long standing papilloedema and not acute papilloedema.', 'role': 'assistant'}]