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: Surgery
All predisposes to oral cancer except - 
Select and explain. 
A. Erythroplakia, B. Leukoplakia, C. Submucosal fibrosis, D. Lichen planus
D: Lichen planus
Answer: D: Lichen planus 
Explanation: None