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': 'Use of Intraaerial cannula in major surgery : \nSelect and explain. \nA. Measurement of direct intra aerial BP, B. Sample for ABG, C. Drug injection, D. All', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D. i.e. All', 'role': 'assistant'}]