<prompt> Which of the following can deliver 90 oxygen?Venturi maskRebreathing O2 maskNasal prongsNon-rebreathing mask with O2reservoir bag  <response>: Non rebreathing masks: Can deliver upto 80 of oxygen. Rebreathing mask: When tightly fit, they can provide 100oxygen.Refer: Morgans Clinical Anaesthesiology, 4th edition, pg no: 38-40 