This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Breathing Systems, Subject name: Anaesthesia
Maximum O2. concentration attained in venture mask is? 
Select and explain. 
A. 90%, B. 100%, C. 60%, D. 80%
C: 60%
Answer: C: 60% 
Explanation: ANSWER: (C) 60%REF: Ajay Yadav 2ad ed p.35Equipment and oxygen delivered in %Nasal canula - 44%Venturi mask - 60%Oxygen mask - 60%Ventilators -100%