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 middle aged female presents with polyarthritis with elevated rheumatoid factorANAanalevels, which among the following will help you to differentiate rheumatoid arthritis from SLE ? \nSelect and explain. \nA. Soft tissue swelling at the proximal inter phalangial joint, B. Juxta articular osteoporosis or X-ray, C. Articular erosions on X-ray, D. Elevated ESR', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]