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 involved in rheumatoid arthritis are all EXCEPT: \nSelect and explain. \nA. PIP, B. DIP, C. MCP, D. Cervical spine', 'role': 'user'}, {'content': "Answer: B \nExplanation: ANSWER: (B) DIPREF: Apley's 8th e p. 51-58Commonly involved joints in RA:WristMCPPIPElbow7KneeAnkleMTPLess commonly involved joints:Upper cervical spine with atlanto axial subluxationHip jointTM jointSubtalar and foot jointsJoints not involved in RA:Lumbar spineDIP", 'role': 'assistant'}]