This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
All are true about N2O except 
Select and explain. 
A. Colour of cylinder is blue, B. Priestly was the first to prepare it, C. Stored in cylinder as gas, D. It is prepared by heating ammonium nitrate
C: Stored in cylinder as gas
Answer: C: Stored in cylinder as gas 
Explanation: Stored in cylinder as gas It is stored as a liquid in the cylinder.