Final answer:
The acre of land that was sold by the resident of Sunny Oaks and is subject to an easement appurtenant for access is known as the B)servient tenement.
Step-by-step explanation:
When the resident of Sunny Oaks sold one acre of land but reserved an easement appurtenant for entrance and exit over that acre to reach the public road, the acre that was sold is known as the servient tenement.
This is because the servient tenement is the parcel of land that is burdened by the easement, meaning it must allow the easement holder (the owner of the dominant tenement) to exercise their rights over the servient property.
Easements are rights to use the property of another for specific purposes and do not typically disappear if the property is sold to a third party; they are generally recorded with the property deed, making them enforceable against subsequent owners.