(a) To be eligible to serve as a trustee a person must be:
(1) a member of the retirement system and an employee of a participating subdivision; or
(2) a retiree of the retirement system.
(b) If a person serving as a trustee ceases to meet an eligibility requirement under Subsection (a), the person shall vacate the office of trustee.
(c) A person serving as trustee who fails to attend four consecutive regular meetings of the board of trustees may not act as a trustee and is considered to have vacated the office of trustee.