The correct answer is d: a target cell's response is determined by the components of its signal transduction pathways. The response of a cell to a hormone depends on the cell’s receptor and a signal transduction. When a peptide hormone binds to a receptor on the cell membrane, a second messenger is activated in the cytoplasm. The second messenger has a role of triggering signal transduction leading to the cellular response. Lots of different signal transduction processes (for example, different intracellular proteins) are used to coordinate the behaviour of target cells.
