This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anaesthetic equipments, Subject name: Anaesthesia
In venturi mask maximum 02 concentration attained is 
Select and explain. 
A. 90%, B. 100%, C. 60%, D. 80%
C: 60%
Answer: C: 60% 
Explanation: In Venturi mask normal O2 concentration is between 24 and 60% . In non breathing masks oxygen saturation is between 80 and 90%.