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: Orthopaedics
[{'content': 'Joint not involved in Rheumatoid arthritis according to 1987 modified ARA criteria? \nSelect and explain. \nA. Knee, B. Ankle, C. Tarsometatarsal, D. Metatarsophalangeal', 'role': 'user'}, {'content': 'Answer: C \nExplanation: According to 1987 modified ARA criteria : -\n\nArthritis of 3 or more joint areas: soft tissue swelling (arthritis) of 3 or more joint areas observed simultaneously by a physician. The 14 possible joint areas involved are, right or left:\n\n\nProximal interphalangeal \xa0\xa0\nMetacarpophalangeal\xa0\xa0\xa0\xa0\xa0\nMetatarsophalangeal\nWrist\nKnee\xa0\nElbow\nAnkle', 'role': 'assistant'}]