This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: X-RAYS, Subject name: Radiology
[{'content': 'Dead bone on an X-ray looks: \nSelect and explain. \nA. More radio-opaque, B. Radiolucent, C. Less radio-opaque, D. Not seen at all', 'role': 'user'}, {'content': 'Answer: A \nExplanation: In chronic osteomyelitis there is dead dense bone in center called sequestrum , which is more radio opaque.', 'role': 'assistant'}]