The largest percentage of carbon dioxide is transported in the blood

In the form of bicarbonate dissolved in the plasma.

Explanation:

A large part of the carbon dioxide is transported dissolved in the plasma. And 10% of CO2 is transported as carbaminohemoglobin.

85% of CO2 Its converted to bicarbonate in the red blood cells of tissues

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.