“Landowner” or “owner of land” means any of the following:
(a) A person or persons shown as the owner of land on the last equalized assessment roll prepared by the county at the time the determination is required to be made pursuant to the requirements of this division. Where that person or persons are no longer the owner, the landowner or owner of land is any person or persons entitled to be shown as the owner of land on the next equalized assessment roll.
(b) Where land is subject to a recorded written agreement of sale, any person shown in the agreement as the purchaser.
(c) Any public agency owning land other than highways, rights-of-way, easements, waterways, or canals.