This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anatomy of skin, Subject name: Dental
[{'content': 'Pterygium of nail is characteristically seen in - \nSelect and explain. \nA. Lichen planus, B. Psoriasis, C. Tinea unguium, D. Alopecia areata', 'role': 'user'}, {'content': 'Answer: A \nExplanation: pterygium unguis is a wing like adhesion between the proximal nail fold and nail bed. Psoriasis-nail pitting. Page no.243. Reference Harrison20th edition', 'role': 'assistant'}]