This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Skeletal system, Subject name: Radiology
[{'content': 'Osteoblastic metastasis is seen - \nSelect and explain. \nA. Prostate carcinoma, B. Multiple myeloma, C. Thyroid carcinoma, D. Renal carcinoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Metastases that are typically purely lytic Kidney Thyroid Metastases that are usually mixed lytic and sclerotic Lung Breast Metastases that are usually purely blastic Prostate Medulloblastoma Bronchial carcinoid', 'role': 'assistant'}]