In a secured loan, collateral is . A) Valuable property that the borrower promises to give the lender in the event of default on the loan.

B) An agreement made in civil court agreeing that the borrower may be arrested in the event of default on the loan.

C) An agreement signed by a co-borrower promising to pay the loan in the event the primary borrower defaults on the loan.

D) And insurance policy taken out by the lender and paid for by the borrower to cover the lender from loss in the event of default.
Please explain.