Final answer:
Objection by one of the parties is the condition that can prevent additional terms from becoming part of a contract between merchants, according to the UCC.
Step-by-step explanation:
The condition that can prevent additional terms from becoming a part of a contract formed between parties who are merchants is objection by one of the parties. In the context of the Uniform Commercial Code (UCC), which governs commercial transactions, when both parties to a contract are merchants.
An additional term included in an acceptance can become part of the contract unless the offer expressly limits acceptance to the terms of the offer, the new terms materially alter the contract, or notification of objection to the new terms has already been given or is given within a reasonable time.