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': 'Ring sequestrum is seen in - \nSelect and explain. \nA. Typhoid osteomyelitis, B. Chronic osteomyelitis, C. Amputation stump, D. Tuberculosis osteomyelitis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Excessive periosteal stripping during amputation may result in ring sequestrum in amputation stump.', 'role': 'assistant'}]