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 papilledema after a head injury except- \nSelect and explain. \nA. Blurring of disc margin, B. Hyperemia, C. Afferent pupillary defect, D. Filling of cup', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Pupillary reactions usually remain fairly normal until late stages.', 'role': 'assistant'}]