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: Dental
The thinnest epithelium of oral cavity is found in the: 
Select and explain. 
A. Buccal gingiva, B. Lingual gingiva, C. Oral surface of lip, D. Sublingual mucosa (floor of mouth)
D: Sublingual mucosa (floor of mouth)
Answer: D: Sublingual mucosa (floor of mouth) 
Explanation: None