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': 'Swan neck deformity seen iri ? \nSelect and explain. \nA. Osteoarthritis, B. Rheumatoid arthritis, C. Pyogenic arthritis, D. Gout', 'role': 'user'}, {'content': 'Answer: B \nExplanation: ANSWER: (B) Rheumatoid arthritis', 'role': 'assistant'}]