Which of the following terms is related to securing a loan with property?

The correct answer, "security interest," refers specifically to a legal claim on collateral that has been pledged by a borrower to secure a loan. When a borrower takes out a loan to purchase property, the lender typically obtains a security interest in that property. This means that if the borrower defaults on the loan, the lender has a right to take possession of the property to satisfy the debt. This concept is foundational in real estate lending, as it provides protection for the lender and helps ensure that the loan is repaid.

In contrast, the other terms pertain to different aspects of real estate and finance. A purchase agreement is a contract between a buyer and seller outlining the terms of a sale but does not involve loan security. A quitclaim transfer relates to the transfer of ownership interest in property without warranties, which is not directly tied to loan security. A lease option involves a tenant's right to purchase the leased property but does not secure a loan in the manner that a security interest does. Thus, "security interest" is the term that correctly aligns with the concept of securing a loan using property.