Final answer:
The activity of MOST cytokines is BEST described as paracrine signaling.
Step-by-step explanation:
The activity of MOST cytokines is BEST described as paracrine. Cytokines are glycoproteins secreted by a wide variety of cells, and they act locally as autocrine or paracrine factors. In the case of cytokines, paracrine signaling occurs when the signaling cell releases the cytokine to target nearby cells. The cytokine then binds to receptors on these nearby cells, eliciting a response.