(a) The retirement system shall deposit all receipts with a depository designated under Section 845.109 or a custodian designated under Section 845.302.
(b) All assets of the pension trust of the retirement system shall be credited according to the purpose for which they are held to one of the following funds:
(1) employees saving fund;
(2) subdivision accumulation fund;
(3) closed subdivision annuity reserve fund;
(4) income fund;
(5) endowment fund; or
(6) expense fund.
(c) Amounts contributed by a subdivision to provide benefits under the optional group term life program for its participating employees and retirees shall be deposited to the optional group term life fund and maintained by the board of trustees as the optional group term life trust.