Which functions do blood cells perform within the capillaries?

Blood cells play crucial roles within the capillaries, and the selected response accurately identifies the key functions they perform. In particular, red blood cells are responsible for transporting oxygen from the lungs to the tissues and organs, where it is essential for cellular respiration. When these cells reach capillaries, they release oxygen to surrounding tissues and simultaneously absorb carbon dioxide, a waste product of metabolism, from those tissues. This exchange process is vital for maintaining homeostasis and supporting cellular function.

In contrast, while binding oxygen is certainly a primary function of red blood cells, the selected answer encompasses a more complete view of the oxygen delivery system in relation to waste elimination. The elimination of only carbon dioxide does not account for the broader waste management roles that occur in the capillaries, where multiple waste products may be exchanged. Producing antibodies is a function of white blood cells, not red blood cells, and while it is an important aspect of the immune response, it does not describe the specific functions within capillaries. Therefore, the identified choice correctly reflects the complex and critical roles that blood cells fulfill in the capillaries during the circulatory process.