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: Surgery
Which of the following gas is most commonly used in laproscopy? 
Select and explain. 
A. CO2, B. N2O, C. O2, D. Helium
A: CO2
Answer: A: CO2 
Explanation: CO2 is used in laproscopy because it is common to the human body and can be absorbed by tissue and removed by the respiratory system. It is also non-flammable, which is impoant because electrosurgical devices are commonly used in laparoscopic procedures.