This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Retina, Subject name: Ophthalmology
[{'content': 'Distance of macula from optic disc is: \nSelect and explain. \nA. 1 mm, B. 2 mm, C. 2.5 mm, D. 4 mm', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]