Which form of co2 transport accounts for the least amount of co2 transported in blood?

Dissolved in plasma

Explanation:

Transport of carbon dioxide in blood occurs in three ways which have been mentioned below -

Only five to seven percent of carbon dioxide is transported by the plasma. It is transported by being dissolved in plasma because carbon dioxide is found to be more soluble in plasma than the oxygen. In form of carbaminohemoglobin nearly 10 percent of carbon dioxide is transported by the RBCs. The major portion of carbon dioxide, which accounts for about 85 percent, is transported in the form of bicarbonate ions as a part of bicarbonate system of our body.

Thus looking at the above three mechanisms of transport of carbon dioxide, it becomes clear now that least amount of carbon dioxide is transported by getting dissolved in plasma.