This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Joint disorders, Subject name: Orthopaedics
Pencil in cup deformity is seen in: 
Select and explain. 
A. Rheumatoid ahritis, B. Ankylosing spondylitis, C. Gout, D. Psoriatic ahritis
D: Psoriatic ahritis
Answer: D: Psoriatic ahritis 
Explanation: Pencil-in-cup deformity--psoriasis Asymmetric oligoahritis is themost common presentationin psoriatic ahritis