This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Peritoneum, Subject name: Surgery
Most common gas used for pneumoperitoneum - 
Select and explain. 
A. Nitrogen, B. CO2, C. O2, D. Air
B: CO2
Answer: B: CO2 
Explanation: Ans. is 'b' i.e., CO2 * First Pneumoperitoneum was created by filtered room air. Carbon dioxide & N20 are now preferred gas because of increased risk of air embolism with room air.