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': 'Which joint is spared in Rheumatoid arthritis - \nSelect and explain. \nA. MP joints of hand, B. DIP joints of finger, C. PIP joints of finger, D. Atlanto-axial joint', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Of particular importance is the sparing of distal interphalangeal joint.', 'role': 'assistant'}]