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: Physiology
[{'content': 'CO2 is primarily transported in the arterial blood as \nSelect and explain. \nA. Dissolved CO2, B. Carbonic Acid, C. Carbamino-hemoglobin, D. Bicarbonate', 'role': 'user'}, {'content': 'Answer: D \nExplanation: CO2 in blood is mainly carried as bicarbonates.', 'role': 'assistant'}]