Which blood component is primarily responsible for oxygen transport?

The correct answer is red blood cells. They are primarily responsible for the transport of oxygen in the bloodstream. This function is accomplished through the presence of hemoglobin, a specialized protein contained within red blood cells that binds oxygen in the lungs and releases it to tissues throughout the body.

While other components of blood play significant roles—such as white blood cells in the immune response, platelets in clotting, and plasma as the liquid medium that carries various substances—none of them are specifically focused on the transportation of oxygen.

Red blood cells constitute a significant portion of blood volume and are uniquely designed for their role, featuring a biconcave shape that increases their surface area for gas exchange and allows them to navigate through the narrowest capillaries.