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: Pathology
Saw tooth retepegs are seen in 
Select and explain. 
A. Lichen planus, B. Leukoplakia, C. Pamphigus vulgaris, D. Psoriasis
A: Lichen planus
Answer: A: Lichen planus 
Explanation: Histology of Lichen planus: