This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anaesthesia
[{'content': 'Fixed performance device is – \nSelect and explain. \nA. Ventury mask, B. Nasal cannula, C. Simple mask, D. Non rebreathing mask', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ventimask (venturi mask) is a fixed performance (high flow) oxygen delivery device.\nNasal cannula, non-rebreathing mask (Hudson mask) and simple mask are variable performance (low flow) devices.', 'role': 'assistant'}]