Answer:
C.) pathogens
Step-by-step explanation:
Among the choices above, it is only the "pathogens" that enter the body in order to multiply and can cause infectious disease or illness to humans. Pathogens refer to disease-causing microorganisms. These organisms include bacteria, virus, fungi, worms, etc.
Phagocytes, antibodies and T cells do not enter the body because they're already inside the body. Phagocytes and T cells are natural cells within the body while antibodies are proteins inside the human body. The phagocytes can be found in the bone marrow, connective tissue. bone tissue, etc. while the T-cells are part of the immune system.