Final answer:
Advocacy is the set of actions one undertakes on behalf of another.
Step-by-step explanation:
Among the given options, the set of actions one undertakes on behalf of another is advocacy. Advocacy refers to the act of supporting, defending, or promoting a cause, idea, or person. It involves taking action to influence or change policies, practices, or attitudes, often on behalf of individuals or groups who may not have the power to do so themselves.