<prompt> A patient suffering from morning stiffness 1 hour, presents with the following abnormality in the X-ray. What can be the most possible diagnosis:Psoriatic arthritisRheumatoid arthritisOsteoarthritisRelapsing polychondritis  <response>: Ans. B Rheumatoid arthritisClassic Swan neck deformityQ DIP joint flexion and PIP joint extension with marked changes at the radiocarpal joint. 