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': 'Which of the following is Non - opioid intravenous anaesthetic agent? \nSelect and explain. \nA. Tramadol, B. Pethidine, C. Fentanyl, D. Ketamine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Intravenous anaesthetic agents divided into two group- Opioids Non opioids Morphine Barbiturates Fentanyl Benzodiazepine Sufentanyl Ketamine Tramadol Etomidate and propofol The most potent opioid issufentanil', 'role': 'assistant'}]