Theoretically,a Nonrebreathing Mask Can Deliver 100% Oxygen,assuming That the Mask

Theoretically,a nonrebreathing mask can deliver 100% oxygen,assuming that the mask fits appropriately on the patient's face and is the only source of gas being inhaled by the patient.However,in actual practice,the disposable nonrebreathing mask can deliver what percentage of FɪO₂?

A) 0.30-0.50
B) 0.40-0.60
C) 0.60-0.80
D) 0.24-0.50