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: Anaesthesia
[{'content': 'True regarding the rubens valve is \nSelect and explain. \nA. Is a non-rebreathing valve, B. Will not allow spontaneous respiration, C. Is a pressure reducing valve, D. May jam in expiratory position', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Rubens valve is a non – rebreathing valve used in self inflating resuscitation bags. It jams in inspiratory position occasionally. It allows spontaneous breathing .', 'role': 'assistant'}]