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
Four numbered instrument formula other than G.M.T. is: 
Select and explain. 
A. Chistle, B. Hoe, C. Angle former, D. Hatchet
C: Angle former
Answer: C: Angle former 
Explanation: None