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
True about N2O: 
Select and explain. 
A. Pin index 3,5, B. Blue in colour, C. Stored as liquid, D. All
D: All
Answer: D: All 
Explanation: A. i.e. Pin index 3, 5 B. i.e. Blue in colour, C. i.e. Stored as liquid