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
[{'content': 'One unit of fresh blood arises the Hb% concentration by - \nSelect and explain. \nA. 0.1 gm%, B. 1 gm%, C. 2 gm%, D. 2.2 gm%', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Whole blood of one unit will raise the Hemoglobin by 1 gm % in an average size adult.', 'role': 'assistant'}]