This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Surgery
In case of massive bleeding during surgery which sized cannula is used? 
Select and explain. 
A. 16 G, B. 20 G, C. 22 G, D. 24 G
A: 16 G
Answer: A: 16 G 
Explanation: Ans. (a) 16G* Grey Venflon is used for blood transfusion during massive bleeding - Size of Grey Venflon =16G.* Green Venflon is commonly used during surgery - Size of green Venflon =18G.