Upon the date fixed for the hearing, or at any time to which it is continued, the board of supervisors shall consider the petition, and any objections which may be filed against it or against the annexation of any territory to the district.

The board of supervisors may by order entered on its minutes grant the petition either in whole or in part, and by order entered on its minutes alter the boundaries of the district, and annex thereto all or such portion of the contiguous territory described in the petition as will be benefited by inclusion in the district.