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: Medicine
[{'content': 'Most common site of sub ependymal astrocytoma (giant cell) - \nSelect and explain. \nA. Trigone of lateral ventricle, B. Foramen of munro, C. Temporal horn of lateral ventricle, D. 4th ventricle', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]