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': 'True about Optic disc : \nSelect and explain. \nA. Horizontal diameter 1.76 mm, B. Veical diameter 1.88 m, C. Contain 1 million nerve fibre, D. All', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C i.e. Contain 1 million nerve fibre', 'role': 'assistant'}]