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': 'In myositis ossificans mature bone is seen - \nSelect and explain. \nA. At periphery, B. In center, C. Whole muscle mass, D. In the joint capsule', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Zonation from the central immature zone of undifferentiated highly active cells to the peripheral mature zone of well-oriented bone is characteristic.', 'role': 'assistant'}]