5. A written contract related to the purchase of the office trailer is subsequently signed, and the terms of the contract reflect that the trailer will be equipped with an HVAC system. The contract also contains language that the terms set forth in the agreement are the complete and exclusive terms of the agreement. Later, when the trailer is delivered to the construction site, your client discovers that it is lacking an HVAC system. When the client calls the seller to object, the seller advises the client that the client's administrative assistant advised, in an earlier telephone call, that HVAC would not be necessary since the people who will be using the trailer are "hardy" and "don't need heat or air conditioning." What provision of the Uniform Commercial Code relates to situations such as this, where a party tries to introduce extrinsic evidence (i.e. evidence that is outside the written contract) in connection with the sale of goods, and what impact would that UCC provision have on the outcome of this dispute? Please fully explain your answer.