Final answer:
The correct answer is C) Inhibition of enzyme activity. Binding of a ligand to a receptor, activation of second messenger, and ion channel opening can stimulate a cellular response, while inhibition of enzyme activity does not.
Step-by-step explanation:
The correct answer is C) Inhibition of enzyme activity. In signal transduction, the binding of a ligand to a receptor, such as a cell-surface receptor, typically triggers a cellular response. This can be achieved through various mechanisms such as the activation of second messengers or the opening of ion channels. However, inhibition of enzyme activity does not necessarily stimulate a cellular response. Enzymes play a crucial role in many cellular processes, and their inhibition can lead to the suppression of specific biochemical reactions or pathways.