Answer:
Mineral rights.
Explanation:
John sold his 10 acre property to Susan and Matt. However, he retained his rights to the oil on the property. John retained his mineral rights. The fact that someone sells his property does not include the mineral rights, they have to be sold separately. The ownership of the mineral rights, in this case, belong to John. Mineral rights are the ones who deal with the ownership of the minerals below the land.
