This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Intravenous Anesthetic Agents, Subject name: Anaesthesia
[{'content': 'What is incidence of emergence delirium after ketamine anaesthesia- \nSelect and explain. \nA. 5% to 30 %, B. 30 % to 55 %, C. 55 % to 70 %, D. 100%', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The observed incidence of emergence delirium after ketamine ranges from 5% to 30 %.', 'role': 'assistant'}]