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': 'Dissociative anaesthesia is produced by: \nSelect and explain. \nA. Ketamine, B. Thiopentone, C. Suxamethoni, D. Diazepam', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ketamine', 'role': 'assistant'}]