Answer:
A) macrophages and monocytes.
Step-by-step explanation:
Mononuclear phagocytes are an important part of cellular immune defenses. Monocytes (which are a part of mononuclear phagocytic system) are the large mononuclear cells found in red bone marrow and they are actively motile and phagocytic (they ingest bacteria), and develop into macrophages when they move to other tissues.
Macrophages are a type of phagocyte that is responsible for detecting, engulfing and destroying pathogens, they are produced through the differentiation of monocytes