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': 'Excretory urography should be cautiously performed in \nSelect and explain. \nA. Bone 2deg, B. Multiple myeloma, C. Neuroblastoma, D. Leukemia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Multiple Myeloma', 'role': 'assistant'}]