Identify the function of platelets in the blood.

Platelets, also known as thrombocytes, play a crucial role in the process of hemostasis, which is the body's mechanism for stopping bleeding. Their primary function is to aid in blood clotting. When a blood vessel is injured, platelets rapidly accumulate at the site of the injury, adhering to the exposed collagen and activating a series of reactions that lead to the formation of a stable blood clot. They release various substances that enhance the aggregation of more platelets and facilitate the repair of the damaged vessel.

In contrast, the other functions listed do not pertain to platelets. For instance, transporting oxygen is a role reserved for red blood cells containing hemoglobin. Fighting infections is primarily managed by white blood cells, which are part of the immune system. Regulating blood pressure is a complex interaction that involves various physiological factors, including the heart, blood vessels, and hormones, rather than the function of platelets directly. Therefore, the role of platelets is specifically centered around their involvement in blood clotting and maintaining hemostasis.