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: Medicine
[{'content': "A 60-year old man with diabetes mieelitus presents with painless, swollen right ankle joint. Radiographs of the ankle show destroyed joint with large number of loose bodies. The most probable diagnosis is - \nSelect and explain. \nA. Charcot's joint, B. Clutton's joint, C. Osteoarthritis, D. Rheumatoid arthritis", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]