Multiple choice CO is transported mainly as ______. bicarbonates dissolved in plasma bicarbonates carried by white blood cells carbonic acid in plasma carbonic acid in RBC Reveal answer Fill a bubble to check yourself A Correct answer Explanation About 70% of carbon dioxide is transported as bicarbonate ions (HCO3-) dissolved in plasma. CO2 enters red blood cells, is converted to carbonic acid by carbonic anhydrase, which dissociates into H+ and HCO3-, with HCO3- moving into plasma.