Final answer:
An interest in real estate that does not include the right to possess is an encumbrance, which affects the property's use but not the transfer of ownership. Easements are typical encumbrances, such as rights to use land for specific purposes without possessing it.
Step-by-step explanation:
An interest in real estate that does not include the right to possess is considered c. an encumbrance. An encumbrance is a right or interest in a property held by someone other than the property owner that does not hinder the transfer of ownership but does affect the property's use. For example, easements are common types of encumbrances that grant the right to use another person's land for a specific purpose, such as access or conservation, but do not confer possession.
In contrast, a leasehold interest (option 'a') involves a tenant's right to occupy and use a property for a specified time. A fee simple estate (option 'b') represents absolute ownership of the property, including the right to possess, use, and dispose of it. A tenancy (option 'd') generally refers to the occupation or possession of land or property by a tenant.