The right answer is the third option (C).
- The pulmonary ventilation that allows the transfer of oxygen from the air that we breathe at the pulmonary alveoli
- Pulmonary diffusion that allows the passage of oxygen through the alveolar-capillary membrane of alveoli with red blood cells that are in pulmonary capillaries
- The circulation of red blood cells from the lungs to the tissues thanks to the heart
- The diffusion of oxygen from the blood which irrigates the tissues up to the cell