What is the legal term for an agreement in which one party makes a promise in exchange for a benefit?

The correct answer is a contract, which is defined as a legally binding agreement that creates an obligation for one or more parties to do (or not do) specific things. In the context of the question, a contract involves one party making a promise in exchange for a benefit or consideration from another party. This mutual exchange of value is what distinguishes a contract from other types of agreements or verbal understandings.

An offer is simply a proposal made by one party to another, signaling the willingness to enter into a contract under specific terms. However, without acceptance and consideration, an offer alone does not constitute a contract.

Agreement refers more broadly to a meeting of the minds between parties, but it does not imply the legal enforceability that a contract has. Additionally, consensus is a term used more informally to indicate general agreement rather than a legally binding arrangement.

In essence, a contract encompasses an agreement supported by consideration, which makes it enforceable under law, making this term the most accurate choice in the context of the question.