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': 'Xylocaine heavy in subarachnoid space has concentration of \nSelect and explain. \nA. 1%, B. 2%, C. 3%, D. 5%', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. 5%', 'role': 'assistant'}]