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': 'Bad prognosis is multiple myeloma is indicated by - \nSelect and explain. \nA. WBC > 20000, B. Azotemia, C. Hypocalcemia, D. Low or normal M component production', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]