This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lichen planus and Other papulosquamous disorders, Subject name: Dental
Lacy White lesions in the mouth with pterygium is seen in: 
Select and explain. 
A. Psoriasis, B. P. Alba, C. Lichen planus, D. Leprosy
C: Lichen planus
Answer: C: Lichen planus 
Explanation: Purple polygonal papules marked by severe pruritus; lacy white markings called as Wickam's Striae, especially associated with mucous membrane lesions & pterygium are diagnostic of Lichen planus.