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: Pharmacology
To minimize the effects of diffusion hypoxia during N2O-O2 analgesia, the patient should be oxygenated for 
Select and explain. 
A. 30 seconds to 1 minutes, B. 3 to 5 minutes, C. 10 to 30 minutes, D. 30 to 45 minutes
B: 3 to 5 minutes
Answer: B: 3 to 5 minutes 
Explanation: None