(a) The board of trustees, by a majority vote of all members, shall appoint an executive director.
(b) The executive director may not be a member of the board of trustees.
(c) To be eligible to serve as the executive director, a person must:
(1) be a citizen of the United States; and
(2) have executive ability and experience to carry out the duties of the office.
(d) The executive director shall recommend to the board actuarial and other services necessary to administer the retirement system.
(e) Annually, the executive director shall prepare an itemized expense budget for the following fiscal year and shall submit the budget to the board for review and adoption.