This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
[{'content': "Differentiating point between psoriatic and rheumatoid ahritis are the following except \nSelect and explain. \nA. Pencil-in-cup deformity, B. Telescoping of phalanges, C. Mael's sign, D. Tufting of phalanges", 'role': 'user'}, {'content': "Answer: C \nExplanation: Mael's sign is the overhanging edge sign of tophaceous gout. Ref - Radiologyassistant.org", 'role': 'assistant'}]