(a) The persons thus associated shall be the trustees of the proposed institution.
(b) Unless they otherwise provide in their charter, the trustees shall annually elect their officers from their number.
(c) Unless otherwise provided by their charter, one-third (1/3) of the whole number of the trustees shall be annually retired from the office, the number to be determined by lot, and others or the same persons shall be elected to fill the vacancies.
(d) The trustees shall hold office until their successors have been elected in the manner provided above.