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
Swan neck deformity seen iri ? 
Select and explain. 
A. Osteoarthritis, B. Rheumatoid arthritis, C. Pyogenic arthritis, D. Gout
B: Rheumatoid arthritis
Answer: B: Rheumatoid arthritis 
Explanation: ANSWER: (B) Rheumatoid arthritis