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': 'Concentration of adrenaline used with lignocaine \nSelect and explain. \nA. 0.180555556, B. 1.430555556, C. 1:20000, D. 1:200000', 'role': 'user'}, {'content': 'Answer: D \nExplanation: local anaesthetic + adrenaline (1:200000)\xa0\n\nFast onset\nLess systemic toxicity\xa0\nProlonged duration', 'role': 'assistant'}]