Final answer:
A special assessment is a specific lien on real property as it is a charge imposed to fund projects that benefit the particular property it is levied against.
Step-by-step explanation:
The question asks which of the following would be a specific lien on real property: unpaid federal income taxes, an easement, a special assessment, or exclusionary zoning. A specific lien is a claim against a particular property for the payment of a debt, such as a mortgage or a mechanic's lien. In this case, option c, a special assessment, is an example of a specific lien. A special assessment is a charge that a local government imposes on real estate owners to fund projects that benefit their property, like improvements to roads or sewer lines directly affecting the property.
Unpaid federal income taxes (option a) would typically lead to a general lien, not specific, against all the taxpayer's assets, not just one piece of property. An easement (option b) is not a lien but rather a legal right to use another person's land for a specific purpose; it does not involve an obligation to pay off a debt. Exclusionary zoning (option d) does not result in a lien at all; rather, it is a regulatory tool used by municipalities to control land use and development.