This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General, Subject name: Skin
Pterygium of nail is seen in? 
Select and explain. 
A. Psoriasis, B. Pemphigus, C. Pemphigoid, D. Lichen planus
D: Lichen planus
Answer: D: Lichen planus 
Explanation: Ans. (d) Lichen planusRef: Roxburg 17th ed p 144, Rooks Thed p 42.1-42.14