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
Which is not a type of Gracey curvettes? 
Select and explain. 
A. # 1-2, B. # 11-12, C. # 13-14, D. # 5-16
D: # 5-16
Answer: D: # 5-16 
Explanation: None