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': 'A 25 year old male is undergoing incision and drainage of abscess under general anaesthesia with Spontaneous respiration. The most efficient anaesthetic circuit is \nSelect and explain. \nA. Maplelson A, B. Mapleson B, C. Mapleson C, D. Mapleson D', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Mapelson breathing systems are classified as Mapelson A, B, C, D, E, F Mapelson A also known as Magill&;s circuit. Ranking of Mapelson&;s systems based on superiority as follows : Spontaneous ventilation : A>D,F,E>C,B Controlled ventilation : D, F, E>B,C>A Mapelson A is more efficient in spontaneous ventilation Mapelson D is more efficient in Controlled ventilation', 'role': 'assistant'}]