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': 'Diencephalon represents - \nSelect and explain. \nA. Lateral ventricle, B. 3rd ventricle, C. 4th ventricle, D. Aqueduct', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]