This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: CNS Tumors, Subject name: Surgery
[{'content': 'Most common site of primary spinal tumor \nSelect and explain. \nA. Intramedullary; Extradural, B. Intramedullary only, C. Intradural; Extramedullary, D. Intra axially only', 'role': 'user'}, {'content': 'Answer: C \nExplanation: - MC spinal tumor - Metastasis - MC primary spinal tumor - Nerve sheath tumor - MC intra - Medullary tumor - Astrocytoma - MC site of primary spinal tumor - Intra-dural; Extra medullary', 'role': 'assistant'}]