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': 'What is the pressure at which oxygen is stored ? \nSelect and explain. \nA. 75 psi, B. 1600 psi, C. 760 psi, D. 2200 psi', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Oxygen is stored at a pressure of 1900psi', 'role': 'assistant'}]