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': 'Investigation of choice for diagnosis and staging of renal cell carcinoma \nSelect and explain. \nA. USG, B. CECT, C. IVP, D. MRI', 'role': 'user'}, {'content': 'Answer: B \nExplanation: IOC\xa0- CECT.\nIOC if renal vein or IVC involved\xa0 - MRI.', 'role': 'assistant'}]