In what way do red blood cells differ from white blood cells?

Red blood cells are characterized by their role in the transportation of oxygen throughout the body, and this function is facilitated by the presence of hemoglobin, a protein that binds to oxygen. In contrast, white blood cells serve a different purpose as they are crucial components of the immune system, responsible for defending the body against infections and foreign invaders. This distinction highlights the fundamental difference between the two types of cells: red blood cells primarily focus on oxygen transport, while white blood cells are integral to immune responses.

The other options do not accurately reflect the differences or roles of these cells. For example, white blood cells are not involved in blood clotting, a function primarily carried out by platelets. Additionally, red blood cells are typically smaller than white blood cells, which misrepresents their size comparison. Lastly, it is the red blood cells that are specifically tasked with oxygen transport, not white blood cells. Thus, the correct choice emphasizes the unique roles and components of each cell type.