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
Perleche is caused by 
Select and explain. 
A. decreased interdental space, B. increased interdental space, C. Lack of Vit-C, D. Trauma to the corners of the mouth
B: increased interdental space
Answer: B: increased interdental space 
Explanation: None