The greatest concentration of CO2 in an adult is found in the:

A pulmonary artery.

B renal artery.

C iliac artery.

D aorta.

A

Explanation:

The pulmonary artery carries de-oxygenated blood from the right ventricle of the heart to the lungs. It is the only artery that carries de-oxygenated blood. This blood is usually from the tissues and has a lot of carbon dioxide from the cellular respiration of cells around the body. The blood is pumped to the lungs to be oxygenated and the carbon dioxide expelled.