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': 'Vesicouretric reflux is demonstrated by \nSelect and explain. \nA. Tc-99 - DTPA, B. Tc-99 - DMSA, C. Tc-99 - MAG-3, D. I - 123 - OIH', 'role': 'user'}, {'content': 'Answer: B \nExplanation: VUR - Tc 99 - DMSA\nGFR estimation Tc 99 - DTPA', 'role': 'assistant'}]