Any interested person, at or before the hearing, may file with the district board a written objection to the creation of the zone or to the inclusion of his property in it. At the hearing the district board shall hear and pass upon all protests and objections. At the conclusion of the hearing, the district board may order that the zone shall be formed or the boundaries of an existing zone be amended, as described in the original resolution, or that any or all properties within such boundaries will not be benefited and shall be excluded.