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': 'Best site for IOL implantation – \nSelect and explain. \nA. Iris, B. Capsular bag, C. Anterior chamber, D. Sulcus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The best position of IOL is within the capsular bag in posterior chamber.', 'role': 'assistant'}]