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 of the following items in the dental operatory cannot be classified as a semi-critical item: 
Select and explain. 
A. Suction tip, B. Handpiece, C. Endodontic file, D. Water syringe tip
C: Endodontic file
Answer: C: Endodontic file 
Explanation: Critical/Non Critical instrument:
Critical: Contact/penetrate/cut tissues e.g. endodontic file, scalpel
Semi Critical: Which touch mucosa BUT donot cut/penetrate tissue e.g. air/water syringe tip, suction tip, handpiece
Non-Critical: Surface disinfection is adequate e.g. X-ray stand, light source