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': 'Conjugate fixation reflex is established by the age of: \nSelect and explain. \nA. 3 weeks, B. 6 weeks, C. 3 months, D. 6 months', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. 6 weeks', 'role': 'assistant'}]