Which of the following terms describes the document that verifies the existence of the loan as secured by the property being purchased?

The term that accurately describes the document verifying that a loan is secured by the property being purchased is the Uniform Commercial Code (UCC) document. In the context of real estate and secured transactions, a UCC filing is a legal form that creditors file to give notice that they have an interest in the personal property of a debtor. This filing is essential because it establishes a public record of the lender's secured interest in the property, thereby protecting the lender's rights if the borrower defaults.

While the other terms may relate to real estate transactions or financing in various ways, none of them specifically serve the purpose of verifying a loan as secured by the property. An as-is agreement pertains to the condition of a property at the time of sale, an estoppel certificate confirms certain details about a lease agreement, and escrow instructions provide guidelines for the handling of funds and documents during a closing process. These documents serve different functions and do not primarily verify loan security in the same manner as a UCC document.