What type of consideration involves a promise to perform an act in the future?

The correct answer refers to executory consideration, which is characterized by a promise to perform an act or provide a service in the future. This type of consideration arises when one party agrees to undertake an obligation that will be fulfilled at a later date. In the context of contract law, an agreement that involves future performance requires valid consideration to be enforceable; hence, executory consideration is an essential element of binding contracts.

In contrast, executed consideration involves something that has already been performed or completed, which does not involve future promises. Past consideration refers to something that was done before the agreement was made, and is generally not valid as consideration in contract law. Sufficient consideration, while important, refers more generally to the adequacy of the consideration provided rather than its temporal aspects. Thus, executory consideration is the type of consideration specifically linked to future promises, distinguishing it from the other options presented.