The board of supervisors shall be deemed to have acquired jurisdiction to proceed further with respect to the formation of a district under any of the following circumstances:
(a) If no protests to the formation of the district are filed at or before the time set for hearing on the formation petition.
(b) If protests are filed and, after hearing, are denied.
(c) If modification of the boundaries of the district is proposed and no objections thereto are filed at or before the time set for hearing objections.
(d) If objections to the modification are filed, and after hearing, are denied.