What legal document grants authority for one person to act on behalf of another?

The legal document that grants authority for one person to act on behalf of another is a Power of Attorney. This document allows an individual, known as the principal, to designate another person, known as the agent or attorney-in-fact, to make decisions and take actions on their behalf. This can include handling financial matters, making legal decisions, or managing healthcare decisions, depending on the type of Power of Attorney.

Using a Power of Attorney is particularly useful when the principal is unable to manage their affairs due to absence, illness, or other reasons. It is a versatile and significant legal tool that ensures the designated agent can perform necessary actions and make decisions as if they were the principal.

In contrast, a Trust Document establishes a trust relationship, controlling assets for the benefit of designated beneficiaries, rather than directly granting authority to act on someone else's behalf. A Will is a legal declaration of a person's wishes regarding the distribution of their estate after they pass away, and it does not grant any authority during the person's lifetime. Power of Choice is not a standard legal term or document recognized in legal practice, so it does not apply in this context. Thus, the Power of Attorney is the correct answer due to its specific legal purpose of granting authority.