What allows someone to act on your behalf in real estate transactions?

The correct choice, power of attorney, is a legal document that allows one person to act on behalf of another in various matters, including real estate transactions. This means that if you grant someone power of attorney, they can make decisions related to buying, selling, or managing property as if they were you. This authority can include signing contracts and documents necessary for real estate deals.

The other options serve different purposes. A real estate license is necessary for someone to legally operate as a real estate agent, but it does not grant the ability to act on someone else's behalf without additional legal authority. A real estate certificate typically refers to a proof of completing a course or training related to real estate, but it also does not confer any authority to act for another person. An agent agreement is a contract between a principal and an agent, outlining the terms and related powers of the agent, but it is not a document that allows a person to act on behalf of another without having been granted the formal power of attorney.