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
Characterstic nail finding in lichen planus 
Select and explain. 
A. Pitting, B. Pterygium, C. Beau's Lines, D. Hyperpigmentation of nails
B: Pterygium
Answer: B: Pterygium 
Explanation: B i.e. Pterygium