“Subdivision,” as used in Section 10249, includes all of the following:
(a) Improved or unimproved land or lands divided or proposed to be divided for the purpose of sale or lease, whether immediate or future, into five or more lots or parcels.
(b) Improved or unimproved land or lands in which, for the purpose of sale or lease, whether immediate or future, five or more undivided interests are created or proposed to be created.
(c) “Subdivision,” as defined in Section 11004.5, excluding “subdivision” as defined in subdivision (e) of that section.