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: Orthopaedics
[{'content': 'A patient developed paraplegia. On routine examination and X-ray it was found that there are osteoblastic lesion in his spine. Most probable diagnosis is - \nSelect and explain. \nA. Carcinoma thyroid, B. Ca. Prostate, C. Breast Ca., D. Pancreatic Ca.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Most common tumor producing osteoblastic bone metastasis is carcinoma prostate.', 'role': 'assistant'}]