Before a plat of any subdivision within the jurisdiction of a county is filed in the office of the county clerk, the plat shall be approved by the board of county commissioners of the county wherein the proposed subdivision lies. The board of county commissioners shall not approve and sign a plat unless the:
A. proposed streets conform to adjoining streets;
B. streets are defined by permanent monuments to the satisfaction of the board of county commissioners; and
C. boundary of the subdivision is defined by permanent monuments.