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': 'First sign of raised intracranial pressure in fundoscopy is \nSelect and explain. \nA. Cupping of optic disc, B. Dilatation of vessels, C. Blurring of disc, D. Nasal shifting of blood vessels', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 1st sign - Dilatation of vessels.', 'role': 'assistant'}]