Final answer:
Neutrophils and macrophages are both types of leukocytes which are white blood cells in the immune system. Neutrophils act as early responders to infection, while macrophages are efficient phagocytes and antigen-presenting cells vital to immune defense.
Step-by-step explanation:
Neutrophils and macrophages are both types of leukocytes. They play essential roles in the body's immune response. Neutrophils are the most numerous type of phagocytes, generally being the first immune cells to arrive at the site of an infection. They engulf and digest pathogens but have a short lifespan, especially after phagocytosing a few pathogens. Macrophages, which develop from monocytes, are large phagocytic cells that can phagocytize a considerable number of pathogens or other cells. They are also versatile, acting as scavengers that rid tissues of worn-out cells and other debris as well as pathogens. Furthermore, macrophages serve as antigen-presenting cells that activate the adaptive immune system.
Addressing the given schoolwork question, the correct answer is C. Leukocytes, as both neutrophils and macrophages are types of white blood cells that help defend the body against infectious disease and foreign materials.