(1) For service retirement, the calculation of benefits payable pursuant to option 2 or 3, as set forth in section 24-51-801, shall be actuarially determined as of the date the retiree attained the age and service requirements for service retirement regardless of the effective date of such retirement.
(2) For reduced service retirement and disability retirement, the calculation of benefits payable pursuant to option 2 or 3, as set forth in section 24-51-801, shall be actuarially determined as of the effective date of retirement.
(3) When a retiree designates a spouse as a cobeneficiary subsequent to retirement pursuant to the provisions of section 24-51-802 (3), the calculation of benefits payable pursuant to option 2 or 3, as set forth in section 24-51-801, shall be actuarially determined as of the date of designation.
(4) When a retiree designates a cobeneficiary subsequent to retirement pursuant to the provisions of section 24-51-802 (3.5), the calculation of benefits payable pursuant to option 2 or 3, as set forth in section 24-51-801, shall be actuarially determined as of the date of designation.