This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Airway, Subject name: Anaesthesia
[{'content': 'Simple face mask (Hudson mask) can deliver maximum FiO2 of:- \nSelect and explain. \nA. 0.6, B. 0.4, C. 0.8, D. 1', 'role': 'user'}, {'content': "Answer: A \nExplanation: Simple facemask/ 'Hudson' mask These devices are used very commonly. They are variable performance devices and the maximum inspired oxygen concentration that can be achieved with these devices is up to 60%, but this is very dependent on the oxygen flowrate and the patient's respiratory pattern. The mask has side holes which are designed to allow indrawing of room air during inspiration", 'role': 'assistant'}]