Which type of encumbrance represents a debt secured by an ownership stake in the property?

The correct answer is a mortgage. A mortgage is a specific type of encumbrance that represents a loan secured by real property. When a property is mortgaged, the owner borrows money from a lender and, in return, grants the lender a security interest in the property. This means that if the borrower fails to repay the loan, the lender has the right to take possession of the property through foreclosure, allowing them to recover the loan amount. In this context, the mortgage acts as a lien on the property, ensuring that the lender has a legal claim to the property until the debt is fully paid off.

Other options, while they relate to property, do not fit the definition of a debt secured by ownership. A lease represents a rental agreement for the use of a property, not a debt. An easement provides a right to use someone else's property for a specific purpose but does not involve a debt or financial interest. Therefore, the mortgage stands out as the correct choice, perfectly encapsulating the idea of an encumbrance tied to a debt secured by ownership.