This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anaesthetic Equipments, Subject name: Anaesthesia
[{'content': 'As per ISO, color of NO2 cylinder is? \nSelect and explain. \nA. Blue, B. Black, C. White, D. Red', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. Blue. (Ref. Lee anaesthesia 12th/pg. 104)COLOR AND PRESSURE OF CYLINDERS CylinderCOLORPRESSURE (BAR)1CyclopropaneOrange52NOBlue543 Grey504HalothaneAmber (Red)-5EthyleneRed-6HeliumBrown1377deg2Black body with white shoulder1378Entonox (50%O2+50%N2O)Blue with white shoulder1379ThiopentoneYellow-10N2Black-11AirGrey with white shoulder137', 'role': 'assistant'}]