What is the term for the assurance by a seller that goods will perform as represented?

The correct term for the assurance by a seller that goods will perform as represented is "warranty." A warranty is a specific type of promise made by the seller concerning the quality, performance, and reliability of the product. It provides the buyer with an expectation that the product will meet certain standards and serves as a form of protection should the goods fail to perform as promised.

Warranties can be expressed, meaning they are explicitly stated, or implied, which means they are suggested by circumstance or commonly accepted standards of the product. This legal assurance allows buyers to have a recourse, such as repair, replacement, or refund, if the product does not meet the outlined conditions.

The other terms, while related, do not specifically capture the legal implications and protections associated with warranties. A guarantee typically serves as a less formal promise about a product's performance but lacks the binding nature of a warranty. A promise is a broad term that doesn’t imply the same formal responsibilities that a warranty does. Assurance, while conveying a sense of reliability, does not encompass the legal obligations and consumer protections that a warranty entails.