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: Gynaecology & Obstetrics
[{'content': 'Media commonly used for distension in hysteroscopy is: September 2011 \nSelect and explain. \nA. Oxygen, B. Carbon dioxide, C. Nitrous oxide, D. Hydrogen', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B: Carbon dioxide The media in common usage for hysteroscopy include carbon dioxide gas delivered through the hysteroflator at a maximum rate of 70 ml/ min and pressure less than 100 mm Hg', 'role': 'assistant'}]