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': 'Earliest radiological feature in rheumatoid ahritis is: \nSelect and explain. \nA. Decreased joint space, B. Juxta aicular osteoporosis, C. Periaicular soft tissue swelling, D. Suhchondral erosions', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. Periaicular soft tissue swelling', 'role': 'assistant'}]