This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anesthesia Machine, Subject name: Anaesthesia
PIN index of nitrous oxide is? 
Select and explain. 
A. 5-Jan, B. 5-Feb, C. 5-Mar, D. 6-Jan
C: 5-Mar
Answer: C: 5-Mar 
Explanation: ANSWER: (C) 3-5REF: Morgan 4th ed p, 20PIN INDEX Air1-5NITROUS OXIDEOxygen2-5* Stored in blue cylinder* Pin index: 3-5* Liquid gas* 745 psi pressure* 1590 lit is the volumeNitrous oxide3-5Carbon di oxide1-6Helox2-4Entonox7