Which of the following clauses relates to a mortgage loan default and requires immediate payment of the debt?

The acceleration clause is a crucial component in mortgage contracts. It stipulates that upon the occurrence of specific events, particularly a default on the mortgage loan, the lender has the right to require the borrower to pay the entire outstanding balance of the loan immediately rather than continuing with regular payments. This clause is designed to protect the lender's interests by allowing them to act swiftly in the event of a borrower's inability to meet their obligations, thus reducing potential losses.

In essence, if a borrower fails to make timely payments or breaches any other terms of the mortgage agreement, the acceleration clause empowers the lender to accelerate the debt, meaning the full amount becomes due and payable. This clause is important as it provides a mechanism for lenders to manage risk and recoup their investments effectively should borrowers default on their loans.