At the final hearing the board of supervisors may make changes in the boundaries of the proposed district, as may be deemed advisable, and shall then describe the boundaries of the proposed district. In doing this:
(a)
No land included in the proposed district in the petition, which will be benefited by the district shall be excluded.
(b)
No land which will not, in the judgment of the board, be benefited by the district shall be included.
(c)
Upon the application of any person whose land was not included in the petition but whose land will be benefited by the proposed district, the land may, in the discretion of the board, be included.