Which of the following best describes a mortgage?

A mortgage is best described as a conditional transfer of property for debt security. This means that when a borrower takes out a mortgage, they are essentially using the property as collateral to secure the loan taken from a lender. If the borrower fails to repay the loan, the lender has the right to take possession of the property through foreclosure.

In this context, the mortgage does not represent the purchase agreement itself, which is a contract between buyer and seller regarding the acquisition of property. It is also distinct from a title deed, which legally indicates ownership of the property. Additionally, a rental lease contract pertains to the lease of a property and does not involve the buying process or securing a loan. Therefore, option B accurately encapsulates the essence of what a mortgage is and how it functions within real estate transactions.