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: Surgery
[{'content': "A 18 year old male presents with a draining sinus on his left leg with pus discharge and discharge of bony pieces since in 3 months. The diagnosis \nSelect and explain. \nA. Chronic osteomyelitis, B. Ewing's Sarcoma, C. Osteoid Osteoma, D. Cellulitis", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Answer- A. Chronic osteomyelitisA history of bone piece discharge from the chronic sinusis considered diagnostic of chronic osteomyelitis.', 'role': 'assistant'}]