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': 'All of the following acts on GABA receptor except \nSelect and explain. \nA. Propofol, B. Thiopentone, C. Etomidate, D. Dexmedetomidine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Dexmedetomidine acts on alpha 2 -adrenoceptor. propofol , thiopentone and etomidate acts on GABA receptor ketamine acts on NMDA receptor', 'role': 'assistant'}]