What is the primary component of blood responsible for oxygen transport?

The primary component of blood responsible for oxygen transport is hemoglobin. Hemoglobin is a protein found in red blood cells that binds to oxygen in the lungs and carries it to tissues throughout the body. Each hemoglobin molecule can carry up to four oxygen molecules, making it highly efficient in transporting oxygen. This function is crucial for maintaining the metabolic activities of cells, as oxygen is vital for energy production.

In contrast, while white blood cells play a critical role in the immune response, they are not involved in oxygen transport. Platelets are essential for blood clotting and preventing bleeding but have no function in carrying oxygen. Plasma, the liquid component of blood, carries nutrients, hormones, and waste products but does not directly transport oxygen. Therefore, hemoglobin is uniquely suited for the role of transporting oxygen in the bloodstream, making it the correct answer.