This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
[{'content': 'Which of the following can deliver 90% oxygen? \nSelect and explain. \nA. Venturi mask, B. Rebreathing O2 mask, C. Nasal prongs, D. Non-rebreathing mask with O2reservoir bag', 'role': 'user'}, {'content': "Answer: B \nExplanation: Non rebreathing masks: Can deliver upto 80% of oxygen. Rebreathing mask: When tightly fit, they can provide 100%oxygen.(Refer: Morgan's Clinical Anaesthesiology, 4th edition, pg no: 38-40)", 'role': 'assistant'}]