Answer:
Breathing out the carbon dioxide
Explanation:
Blood is the medium through which carbon dioxide is transported to the lungs from where it is exhaled out.
The Carbon dioxide produced in cells after respiration diffuses into the blood in exchange of oxygen delivered to the cells for further respiration. Blood while flowing through the lungs passes carbon dioxide to its alveoli which is then exhaled out and oxygen is inhaled from outside.
Hence, cell keep the carbon dioxide from building up in the cytoplasm and poisoning the cell by exhaling CO2.