This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Rheumatoid Arthritis, Subject name: Orthopaedics
[{'content': 'Joint spared in RA - \nSelect and explain. \nA. PIP, B. DIP, C. MCP, D. Wrist', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., DIP JointImportant arthritis i nvoiving the j ointDistai interphalangeal jointProximal interphalangeal jointMetacarpophalangeal joint1st Carpometacarpal jointWristOsteoarthritis, Psoriatic arthritis. Reactive arthritisOsteoarthritis, RA, SLE, Psoriatic arthritisRA, pseudogout, hemochromatosisOsteoarthritisRA, Pseudogout, gonococcal arthritis, juvenile arthritisSpared joint o Wrist and MTPo DIPOsteoarthritisRA", 'role': 'assistant'}]