Final answer:
An offeree can use an option contract, providing something of value in exchange for the offeror's promise to keep the offer open for a set time, or a firm offer under the UCC, requiring no consideration for the offer to remain open within a specified duration.
Step-by-step explanation:
An offeree can ensure that an offer will stay open for a set period of time by entering into an option contract with the offeror. This is a separate contract in which the offeree provides consideration (something of value) in exchange for a promise from the offeror to keep the offer open for a specified duration. Without an option contract, the offer can typically be revoked at any time before acceptance under common law. Another way is to include a provision in the initial offer stipulating a fixed period during which the offer will remain open and cannot be revoked; this is known as a firm offer. Firm offers are commonly used in commercial transactions and are recognized under the Uniform Commercial Code (UCC) when made by a merchant in a signed writing that assures the offer will be held open. It is worth noting that while option contracts require consideration, firm offers do not, making this an attractive choice for an offeree in goods transactions.