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 wavelength of diode laser is: 
Select and explain. 
A. 637 nm, B. 1064 nm, C. 670 nm, D. 515 nm
C: 670 nm
Answer: C: 670 nm 
Explanation: None