Which is not an example of intracellular communication?

a.

ions are exchanged in a nerve cell stimulating other ion changes in that same cell.

b.

a chemical released in a cell stimulates another part of that same cell.

c.

a chemical release in a muscle cell causes the release of a second chemical in that same cell.

d.

a pheromone molecule in the air produced by one insect stimulates a reaction in a cell of another insect.