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
CO2 is primarily transported in the arterial blood as 
Select and explain. 
A. Dissolved CO2, B. Carbonic Acid, C. Carbamino-hemoglobin, D. Bicarbonate
D: Bicarbonate
Answer: D: Bicarbonate 
Explanation: CO2 in blood is mainly carried as bicarbonates.