Final answer:
A merchant's firm offer under Article 2 of the UCC requires that both the offeree and the offeror are merchants, a signed writing is used to make the offer, and the offer includes a specific time frame for its validity.
Step-by-step explanation:
A merchant's firm offer under Article 2 of the Uniform Commercial Code (UCC) requires several elements. One of the requirements is that both the offeree and the offeror are merchants, meaning they are engaged in the business of buying and selling goods. Another requirement is that the offer is made in a signed writing, which can be in the form of a written assurance signed by the offeror. Lastly, the offer must contain a specific time frame within which it will remain open.