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
The most common benign tumor occurring in oral cavity is: 
Select and explain. 
A. Papilloma, B. Fibroma, C. Adenoma, D. Epulis
B: Fibroma
Answer: B: Fibroma 
Explanation: None