Final answer:
Lymphatic vessels are part of the lymphatic system, responsible for removing excess interstitial fluid from tissues and playing a key role in the body's immune response by transporting and filtering lymph through lymph nodes.
Step-by-step explanation:
The question pertains to the function of lymphatic vessels within the lymphatic system. The correct function is that they remove excess fluid from interstitial spaces. Lymphatic vessels make up a critical part of the lymphatic system, which is comparable but distinct from the cardiovascular system. Unlike arteries, these vessels carry lymph fluid, which is a clear fluid that originates from the interstitial spaces between cells after being leaked from the blood capillaries. This fluid enters the lymph capillaries and then travels through the lymphatic system, eventually being returned to the bloodstream near the heart.
The system plays a fundamental role in the immune response by transporting lymphocytes and filtering the lymph through the lymph nodes, where pathogens are removed before the lymph is returned to the bloodstream. As part of the immune system, the transportation and filtration through lymph nodes serve to prevent and fight infections by removing infectious agents such as bacteria and viruses.