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': 'With a fixed performance mask such as a ventimask \nSelect and explain. \nA. Rebreathing is possible, B. Plugging side holes increases the oxygen concentration, C. Total gas flow is higher than the patient’s peak inspiratory flow, D. There is high equipment dead space', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Dead space in ventimask is low and rebreathing is not possible because of high flow of gas.', 'role': 'assistant'}]