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
In DMF index, according to WHO specification teeth missing due to any other reason other than caries is designated as 
Select and explain. 
A. D, B. M, C. F, D. None of the above
D: None of the above
Answer: D: None of the above 
Explanation: None