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: Anaesthesia
Pin code index of nitrous oxide is: March 2013 (c) 
Select and explain. 
A. 1, 6, B. 2, 5, C. 2, 6, D. 3, 5
D: 3, 5
Answer: D: 3, 5 
Explanation: Ans. D i.e. 3, 5