A landowner owned a large parcel of land that he divided into two equal parcels. Thirty years ago, the landowner deeded the eastern parcel to a purchaser by warranty deed, including an easement over the south 25 feet of the western parcel for access to the navigable river that ran along the westerly boundary of the western parcel. The landowner acknowledged the deed and easement, and the purchaser recorded the document. The recording officer maintains an alphabetical grantor-grantee index, but no tract index.

The purchaser made no use of the easement until five years ago, one year after her neighbor had purchased the western parcel from the landowner. The neighbor had paid at least market value for the western parcel and was not aware of the purchaser's easement. The neighbor objected to the purchaser's use of the easement shortly after she began using it, but the purchaser paid no attention. The neighbor sues the purchaser to quiet his title and to restrain the purchaser from using the easement over the western parcel. The purchaser has reasonable access to a public highway on the easterly boundary of the eastern parcel.

If the purchaser is successful, what is the likely reason?

A The absence of a tract index requires that the neighbor make inquiry regarding the riparian rights of owners abutting his property.
B The neighbor and the purchaser trace their title to a common grantor, the landowner, whose covenants for title run with the land and estop the neighbor from denying the purchaser's title.
C An easement is a legal and incorporeal interest that is not just attached to an estate in the land, but runs with the land itself and therefore binds successive owners of the servient estate regardless of notice.
D The easement is a legal interest in the neighbor's chain of title even though there is no tract index.