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: Unknown
[{'content': 'Most common malignant brain tumor \nSelect and explain. \nA. Astrocytoma, B. Glioblastoma multiforme, C. Oligodendroglioma, D. Ependymoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B Glioblastoma multiforme Ref: Sabiston.Page 1371 The following data should be remembered for brain tumors- Most common malignant Brain tumor: Secondaries > Gliomas > Meningiomas > Astrocytomas.', 'role': 'assistant'}]