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: Surgery
[{'content': 'You want assistant to get entonox gas cylinder ,which color will you order him to get? \nSelect and explain. \nA. Black body white shoulder, B. Blue body white shoulder, C. White body black shoulder, D. White body blue shoulder', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Entonox has blue body with white shoulder color code for cylinder', 'role': 'assistant'}]