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: Medicine
[{'content': 'A patient presents with acute renal failure with normal ultrasound abdomen repo. Next most useful investigation is : \nSelect and explain. \nA. Intravenous pyelography, B. DTPA scan, C. Retrograde pyelography, D. X-ray abdomen and CT scan.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Answer is B (DTPA scan): The next step would he to assess Renal function which is best achieved by DTPA scan amongst the options provided.', 'role': 'assistant'}]