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: Radiology
[{'content': 'Which tumors suggested by "Trouser leg appearance" on an ascending myelogram? \nSelect and explain. \nA. Extradural, B. Extramedullary, C. Intramedullary, D. Vertebral', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Trouser leg appearance on myelography is seen in intramedullary block.', 'role': 'assistant'}]