Some bacterial cells secrete a chemical that allows other bacterial cells to determine the density of bacterial cells in the area. They use this to determine if their population is large enough to begin certain functions, like forming a protective biofilm together.

Based on this type of chemical signaling, which of the following demonstrates the same type of chemical signaling?

A. B cells engage in cell-to-cell recognition with helper T cells, exchanging antigen information the B cell has on its cell surface.
B. Cells that secrete oxytocin also use oxytocin for autocrine signaling, helping it to down-regulate production when needed.
C. During development, human nerve cells participate in paracrine signaling to determine what other nerve-cell types are in the area to adjust their placement.
D. Some animal cells can form junctions with other animal cells to directly share information.