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
[{'content': 'In case of massive bleeding during surgery which sized cannula is used? \nSelect and explain. \nA. 16 G, B. 20 G, C. 22 G, D. 24 G', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 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.', 'role': 'assistant'}]