Answer:
D. Cell signalling which is released by one type of cell and acts upon a different cell
Explanation:
According to this question, adrenal cells near the kidney releases an hormone called ADRENALINE, which causes the cells of the heart to beat faster. This is an example of CELL SIGNALLING because chemical signals released by adrenal glands causes/triggers a response in the heart cells.
The chemical signal released by the adrenal cells is the ADRENALINE HORMONE, which induces a response in cells that are different from the cells of release (adrenal cells).