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
Tip of ultrasonic scaler after usage, cleaned by 
Select and explain. 
A. Under running H2O for 2 min, B. chemical cleaning, C. Autoclave, D. Not Recalled
C: Autoclave
Answer: C: Autoclave 
Explanation: None