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: Anatomy
[{'content': 'The retina is an outgrowth of the - \nSelect and explain. \nA. Mesencephalon, B. Diencephalon, C. Telencephalon, D. Pons', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]