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: Unknown
The Pin index code of Nitrous oxide is : 
Select and explain. 
A. 2,5., B. 1,5., C. 3,5., D. 2,6.
C: 3,5.
Answer: C: 3,5. 
Explanation: Ans. is 'c' i.e. 3, 5 Pin index for the following gases are-Nitrous oxide - 3 and 5Oxygen - 2 and 5Cyclopropane - 3 and 6Carbon dioxide - 1 and 6 Also, RememberInternational color code for cylindersOxygen* - black with white shouldersNitrous oxide* - BlueCarbon dioxide* - GrayCyclopropane*- Orange