What happens to oxygen during the gas exchange with body cells?

The process of gas exchange with body cells involves the uptake of oxygen from the bloodstream and the release of carbon dioxide as a waste product. In the tissues, the cells utilize oxygen for cellular respiration, which is essential for producing energy. During this process, carbon dioxide is generated as a byproduct and diffuses from the cells into the bloodstream to be transported back to the lungs for exhalation.

Option A accurately describes this essential physiological process, emphasizing the role of body tissues in taking up oxygen and releasing carbon dioxide. This exchange is critical for maintaining cellular function and overall metabolic processes.

The other options do not correctly depict what occurs during gas exchange. Oxygen is not primarily stored in muscles; rather, it is used immediately by cells for energy production. While some organisms may have unique ways of managing gases, humans do not expel oxygen through the skin, as the primary mode for oxygen release is through respiration in the lungs. Option D also mischaracterizes the gas exchange process, as carbon dioxide is transported from the tissues to the lungs rather than being absorbed directly from lung tissue.