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': 'The best investigation for parameningeal rhabdomyosarcoma: \nSelect and explain. \nA. CSF cytology, B. MRI, C. CECT, D. SPELT scan', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. MRI', 'role': 'assistant'}]