This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Joint disorders, Subject name: Orthopaedics
[{'content': 'Joint not involved in Rheumatoid ahritis according to 1987 ACR CLASSIFICATION CRITERIA ? \nSelect and explain. \nA. Knee, B. Ankle, C. Tarsometatarsal, D. Metatarsophalangeal', 'role': 'user'}, {'content': 'Answer: C \nExplanation: ref : maheswari 9th ed', 'role': 'assistant'}]