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
All of the following acts on GABA receptor except:- 
Select and explain. 
A. Thiopentone, B. Propofol, C. Zolpidem, D. Ketamine
D: Ketamine
Answer: D: Ketamine 
Explanation: Ketamine acts on NMDA receptor. Xenon and nitrous oxide also acts on NMDA receptor. Rest other intravenous and inhalational agents act on GABA receptor.