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': "Sclerotic lesion in the bone is seen in all except - \nSelect and explain. \nA. Osteitis fibrosa, B. Osteopetrosis, C. Melorheostosis, D. Caffey's disease", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]