Section 153A-330 authorizes counties to regulate subdivisions, which are defined by § 153A-335 as the sale of two or more lots of less than 10 acres from previously undivided land, excluding the division of less than two acres into no more than three lots. If a county has chosen to zone only portions of its jurisdiction, it may adopt subdivision regulations that apply only within those portions. Section 153A-331 allows counties to include provisions in their subdivision ordinances to ensure the following: the public dedication or reservation of rights-of-way or easements for street and utility purposes; the coordination of streets and other public facilities within a proposed subdivision with existing or planned streets or other public facilities located outside the subdivision; the construction of community service facilities; the posting of a bond to guarantee compliance with the ordinances; the dedication of land or payment of a fee to provide for a recreation area; the construction of street improvements or payment to the county to provide therefore; and the preparation, approval, and recordation of a plat whenever any subdivision of land takes place. Additionally, the county may require the reservation of school sites in accordance with its comprehensive plan; to do so, however, the county and the board of education must first have determined the specific location and size of each school site and have included that information in the comprehensive plan. Under § 153A-332 a county may give the district highway engineer, the county health director or local public utility, and any other agency or official designated by the board of commissioners an opportunity to make recommendations on a plat before it is approved. After the ordinance has been adopted, all subdivision plats must be approved prior to being filed or recorded. The ordinance may give final-approval authority to the county board of commissioners, the board of commissioners on recommendation of a planning agency; or a designated planning agency.