This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Skin
[{'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: A i.e. Lichen planus', 'role': 'assistant'}]