This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Preoperative assessment and monitoring in anaesthesia, Subject name: Anaesthesia
Laryngeal mask airway is used for 
Select and explain. 
A. Airway maintenance, B. Cardiopulmonary resuscitation, C. Positive pressure ventilation, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Laryngeal mask airway is used in airway maintenance, cardiopulmonary resuscitation, positive pressure ventilation