Final answer:
Chemokines are molecules that serve as chemotactic factors for leukocytes. They are specific in terms of the leukocytes they target and guide these leukocytes to sites of infection, inflammation, or tissue damage.
Step-by-step explanation:
The correct answer to the question is C: Chemokines are chemotactic factors for leukocytes. Chemokines are molecules that attract leukocytes, such as white blood cells, to sites of infection, inflammation or tissue damage. These chemotactic factors are highly specific in the subsets of leukocytes they target. Leukocytes in the blood respond to these chemotactic factors by following chemical attractants released by pathogens and signals from injured cells.
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