At the time and place provided in the notice or at any time and place to which the hearing is adjourned, the board or its appointed hearing officer shall hear all the following:
(a) The petition for exclusion or reduction.
(b) All evidence or proofs that may be introduced by or on behalf of the petitioners.
(c) All objections to the petition that may be presented in writing by any person, including the district.
(d) All evidence or proofs that may be introduced in support of objections to the petition.