This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Alopecia, Subject name: Skin
[{'content': 'Coarse pitting of nails is seen in? \nSelect and explain. \nA. Psorati carthiritis, B. Dermatitis herpetiformis, C. Bullous pemphigoid, D. Pemphigus vulgaris', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. (a) Psoratic arthiritisRef: Rook's 8/e, p 65.13", 'role': 'assistant'}]