Which of the following is a type of encumbrance?

The correct answer highlights a mortgage or lien as a type of encumbrance that affects a property's title. Encumbrances refer to claims, liens, or liabilities attached to a property that may affect its transferability or use. A mortgage is a specific legal claim against a property used as security for a loan, meaning that the lender has a right to take possession of the property if the borrower defaults. Similarly, a lien represents an obligation that the property owner must address, typically associated with unpaid debts like property taxes or contractor fees. Both of these encumbrances impact the title, as they create financial obligations that must be resolved before clear ownership can be transferred.

The other options do not accurately describe encumbrances. A rental agreement illustrates an important relationship between a landlord and tenant but does not encumber the title of the property. Property zoning restrictions regulate how a property can be used but are not classified as encumbrances in the same legal sense as a mortgage or lien. A surveyor's report pertains to property boundaries and provides important information regarding the property’s physical attributes, but it does not impose a legal obligation or a financial claim on the property, thus not fitting the definition of an encumbrance.