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': 'The following are used for treatment of postoperative nausea and vomiting following squint surgery in children except:- \nSelect and explain. \nA. Propofol, B. Ketamine, C. Dexamethasone, D. Ondansetron', 'role': 'user'}, {'content': 'Answer: B \nExplanation: ketamine does not have antiemetic effect, among anaesthetic agent propofol has antiemetic effect. even benzodiazepine has antiemetic effect , midazolam has best antiemetic effect among them.', 'role': 'assistant'}]