A lender can require a borrower to pay before the scheduled due date through which clause?

The correct choice here is the demand clause. This clause allows a lender to call a loan due before its scheduled maturity date if certain conditions are met. The demand clause grants the lender certain rights if they feel that their security (the loan) is at risk or if the borrower's creditworthiness has diminished. This means that the lender has the power to request full repayment of the outstanding loan amount, often if they see changes in the borrower's financial situation or if the collateral securing the loan has decreased in value.

Understanding this clause is crucial in real estate lending because it gives lenders a mechanism to protect their investment in cases where they see potential issues with the borrower's ability to repay. The other choices refer to different concepts: a prepayment clause allows borrowers to pay off loans early under specified conditions, an acceleration clause enables the lender to demand full repayment if the borrower defaults, and an amortization clause defines the loan repayment schedule. Each serves a specific purpose in lending agreements but the demand clause specifically addresses the lender's ability to require repayment at their discretion.