This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Physiology
[{'content': 'Best vehicle for oxygen is \nSelect and explain. \nA. Hb solution, B. Whole blood, C. Plasma, D. Dissolved', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 97% of oxygen in blood combines with Hb and presence of Hb increases the oxygen carrying capacity of blood 70 fold.3% of blood os transpoed in dissolved form.ie 100 ml of pure blood contains 0.3ml of oxygen dissolved in plasma.Ref: Textbook of medical physiology by N Geetha, 2nd edition, page no. 241,242', 'role': 'assistant'}]