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: Radiology
[{'content': '"Sharpened Pencil" appearance of mandibular condyle on radiograph indicates: \nSelect and explain. \nA. Osteoarthritis, B. Rheumatoid arthritis, C. Infectious arthritis, D. Juvenile arthritis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]