Final answer:
The correct option is b) Cytokines communicate among parts of the immune system.
Step-by-step explanation:
The correct option that is matched with its primary function is option b) Cytokines communicate among parts of the immune system.
Cytokines are signaling molecules that are secreted by immune cells to communicate with each other. They play a key role in coordinating the immune response and are involved in inflammation, immune cell activation, and regulation of immune responses.
For example, Interleukin-1 (IL-1) is a cytokine that triggers inflammation by promoting the expression of adhesion molecules and inducing the production of other pro-inflammatory cytokines. Another example is Interferons, which are cytokines that are produced in response to viral infections and help to inhibit viral replication and stimulate immune responses.