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': 'Fixation reflex develops at the age of \nSelect and explain. \nA. 2-4 months, B. 4-6 months, C. 6-8 months, D. 5-7 years', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Fixation reflex 2-4 months.\nMacular differentiation 4-6 months.\nStereopsis 5-7 years.', 'role': 'assistant'}]