This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anesthesia Circuit, Subject name: Anaesthesia
Which of the following is main determinant of carbon dioxide elimination is Mapelson circuit: 
Select and explain. 
A. Type of circuit, B. Fresh gas flow, C. Type of ventilations, D. Age of patient
B: Fresh gas flow
Answer: B: Fresh gas flow 
Explanation: Any mapelson circuit can be used for any type of ventilation just by varying fresh gas flow. Required fresh gas flow Spontaneous controlled Mapelson A - Equal to minute ventilation very high Mapelson D - 2-3 x minute ventilation(MV) 1-2 x MV