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: Unknown
[{'content': 'Central macular fixation developed at : \nSelect and explain. \nA. 3 weeks, B. 3 months, C. 6 weeks, D. 6 months', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The critical period of developed of fixation reflex is 5-6 months of age.\nThis is the reason why unilateral cataracts in children should be operated early. Remember –\nBinocular vision develops at 5-6 years.', 'role': 'assistant'}]