Which of the following is a clause that could make a mortgage balance due if the borrower defaults?

The correct choice is an acceleration clause, which is a critical component in mortgage agreements. This clause allows the lender to demand the full balance of the loan to be paid immediately if the borrower defaults on the mortgage. Default can occur for various reasons, such as failing to make timely payments or violating other terms of the loan agreement. When the acceleration clause is invoked, the lender has the right to accelerate the payment schedule, requiring the borrower to pay off the entire remaining mortgage balance rather than just the monthly payments.

Understanding the role of the acceleration clause is essential for both borrowers and lenders in real estate transactions, as it outlines the consequences of default. Other clauses mentioned, such as a prepayment penalty, typically pertain to fees for paying off a loan early, while a due-on-sale clause allows the lender to call the loan due when the borrower sells the property. A subordination clause involves the hierarchy of liens on the property rather than addressing the default itself. This differentiation helps clarify the enforcement of loan terms in cases of borrower distress.