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': 'Macula is \nSelect and explain. \nA. Optic nerve, B. Optic tract, C. Periodic bluring of vision, D. Constant blinking', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. Constant blinking', 'role': 'assistant'}]