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': 'Following are steps of rapid sequence intubation except \nSelect and explain. \nA. i.v thiopentone + i.v succinylcholine is used for paralysis with induction, B. Bag and mask ventilation is used for positive pressure ventilation., C. Sellick’s maneuver is used to prevent aspiration, D. Pre-oxygenation is mandatory.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Bag and maskventilation is contraindicated in rapid sequence intubation because of risk of aspiration.', 'role': 'assistant'}]