(a) The board of trustees shall appoint a director.
(b) The director shall manage and administer the retirement system under the supervision and direction of the board.
(c) The board of trustees may delegate to the director powers and duties in addition to those stated by Subsection (b).
(d) The director annually shall:
(1) prepare an itemized budget showing the amount required to pay the retirement system's administrative expenses for the following fiscal year; and
(2) submit the administrative budget to the board for review, amendment, and adoption.