Which of the following accurately describes the role of hemoglobin?

The role of hemoglobin is primarily to carry oxygen to the cells of the body. Hemoglobin is a protein found in red blood cells that binds to oxygen in the lungs and transports it through the bloodstream to various tissues and organs. This is a critical function, as oxygen is essential for cellular metabolism and energy production in the body.

Through its ability to bind oxygen, hemoglobin also assists in the removal of carbon dioxide, a waste product of metabolism, by carrying it back to the lungs for exhalation. This dual role is essential for maintaining proper physiological function and overall health.

The other options describe different functions in the body that are not associated with hemoglobin. For instance, while the immune system protects against infections, hemoglobin does not have a role in immune response. Similarly, regulating body temperature and transporting nutrients are functions performed by other systems and proteins in the body, such as the circulatory system and various transport proteins, rather than by hemoglobin. Thus, the accurate description of hemoglobin's role is its function in oxygen transport.