Question

what is one type of immune cell that relies on active transport? stem cells macrophages red blood cells

Explanation:

Macrophages are immune cells that use active transport (such as phagocytosis - a form of endocytosis, an active process) to engulf pathogens and cellular debris. Stem cells are undifferentiated cells that can give rise to various cell types but are not primarily defined by active transport in immune function. Red blood cells are not immune cells; their main function is gas transport (oxygen and carbon dioxide) via passive processes like diffusion.

Answer:

macrophages