This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ohopaedics Q Bank, Subject name: Orthopaedics
[{'content': 'Which of the following most commonly produces osteoblastic secondaries? \nSelect and explain. \nA. Carcinoma lung, B. Carcinoma breast, C. Carcinoma urinary bladder, D. Carcinoma prostate', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Most common tumor producing osteoblastic bone metastasis is carcinoma prostate. Purely Osteoblastic secondaries are produced by Ca.prostate, Ca.Breast, carcinoid tumor and medulloblastoma.', 'role': 'assistant'}]