What is the primary function of the lymphatic system?

The primary function of the lymphatic system is to transport lymph, which is a clear fluid that contains white blood cells and other substances. This system plays a crucial role in filtering pathogens, such as bacteria and viruses, from the lymph as it passes through the lymph nodes. The lymphatic system also helps maintain fluid balance in the body by returning excess interstitial fluid to the bloodstream, preventing tissue swelling.

By filtering and trapping pathogens, the lymphatic system contributes to the body's immune response, allowing white blood cells to recognize and respond to infections effectively. Thus, the transportation of lymph, filtration of pathogens, and maintenance of fluid balance are central to its function, making this option the most comprehensive and accurate choice in relation to the lymphatic system’s purpose.