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
Leukoplakia with the worst prognosis is seen on the: 
Select and explain. 
A. Dorsum of tongue, B. Floor of mouth, C. Buccal mucosa, D. Palate
B: Floor of mouth
Answer: B: Floor of mouth 
Explanation: None