Which system provides for the oxygenation of blood and the elimination of carbon dioxide?

The respiratory system is essential for the oxygenation of blood and the elimination of carbon dioxide. This system involves the process of breathing, which includes inhalation and exhalation. During inhalation, oxygen from the air enters the lungs and diffuses into the bloodstream, where it binds to hemoglobin in red blood cells. At the same time, carbon dioxide, a waste product of cellular metabolism, diffuses from the blood into the lung's alveoli to be exhaled. This constant exchange of gases is crucial for maintaining the body’s respiratory function and ensuring that cells receive the oxygen they need for energy production while removing carbon dioxide to prevent toxic buildup.

In contrast, the muscular system is primarily responsible for movement and stabilization of the body, the circulatory system's main function is transporting blood throughout the body rather than directly oxygenating it. The nervous system plays a role in coordinating bodily functions, including those of the respiratory system, but it does not directly engage in gas exchange itself. Thus, the respiratory system is the correct choice for the primary process of oxygenating blood and eliminating carbon dioxide.