Answer:
Generally, an easement "runs with the land" unless the original grant specifies it will end when the grantee no longer owns the property.
If A granted a right of way easement over their land to B then the ROW will become an appurtenant right attached to B's land. When B sells to a new owner, the new owner also will acquire the ROW. However, B cannot sell or transfer the ROW to any other land owner, for example, her neighbor, C.