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': "Ramesh 60 years, presents with generalized bone pain. On examination there is elevated ESR of 100 mm, serum globulin 7, lytic lesions in the skull, serum creatinine of 3.5 mg/dL and serum calcium of 11mg/dL. What is the most likely diagnosis - \nSelect and explain. \nA. Waldenstrom's macroglobulinemia, B. Multiple myeloma, C. Hyperparathyroidism, D. Osteomalacia", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]