This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inhalational Anesthetic Agents, Subject name: Anaesthesia
[{'content': 'Which is wrong regarding entonox? \nSelect and explain. \nA. Is used for labor analgesia, B. Is a mixture of nitrous Oxide and oxygen in the ratio of 50: 50, C. Pin index is 7, D. Can be used for anesthesia', 'role': 'user'}, {'content': "Answer: D \nExplanation: Entonox is used for analgesia not anesthesia. Entonox (Nitrous oxide and oxygen) is a colourless, odourless gas made up of half oxygen and half nitrous oxide. It's also known as laughing gas. It can take the edge off labour pain, rather than blocking it out", 'role': 'assistant'}]