This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Skeletal System, Subject name: Radiology
A patient suffering from morning stiffness >1 hour, presents with the following abnormality in the X-ray. What can be the most possible diagnosis: 
Select and explain. 
A. Psoriatic arthritis, B. Rheumatoid arthritis, C. Osteoarthritis, D. Relapsing polychondritis
B: Rheumatoid arthritis
Answer: B: Rheumatoid arthritis 
Explanation: Ans. B Rheumatoid arthritisClassic Swan neck deformityQ (DIP joint flexion and PIP joint extension) with marked changes at the radiocarpal joint.