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
Pin index for Air is 
Select and explain. 
A. 1,4, B. 2,5, C. 5, D. 1,5
D: 1,5
Answer: D: 1,5 
Explanation: PIN index number prevents wrong fitting of the cylinders . AIR - 1 ,5 02 - 2 ,5 N20 - 3 ,5 CO2 - 1 ,6 ; 2,6(Liquid) Cyclopropane 3 ,6 Entonox 7