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
Gingival Col is: 
Select and explain. 
A. Orthokeratinized, B. Para keratinized, C. Both para and ortho keratinized, D. Non-keratinized
D: Non-keratinized
Answer: D: Non-keratinized 
Explanation: None