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 world health organization's objective in dental health is that by the year 2000 a person, at age of 12, shall not have decayed, missing and filled teeth (DMF) more than: 
Select and explain. 
A. 1, B. 2, C. 3, D. 4
C: 3
Answer: C: 3 
Explanation: None