Which document signifies a borrower's commitment to repaying a loan?

The promissory note is the document that signifies a borrower's commitment to repaying a loan. It is a legally binding written promise to pay a specified amount of money at a predetermined time, and it outlines the terms of the loan, including the interest rate and repayment schedule. This document is critical in establishing the borrower's formal obligation to repay the loan, making it a cornerstone of the lending agreement.

While the mortgage, loan agreement, and security deed are all important documents in the lending process, they do not specifically represent the borrower's commitment to repayment in the same way the promissory note does. The mortgage serves as security for the loan, giving the lender the right to foreclose if the borrower defaults, while the loan agreement encompasses the terms and conditions of the loan. The security deed, typically used in certain states, also conveys the property interest to the lender but does not encapsulate the borrower's promise to repay as clearly as the promissory note. Thus, the promissory note is distinctively focused on the borrower's obligation, making it the correct answer in this context.