(

a) Notwithstanding

Section or 31786, upon the death of any member after retirement for service-connected disability, the member’s retirement allowance as it was at the member’s death if not modified in accordance with one of the optional settlements specified in

Article 11 (commencing with

Section 31760), shall be continued to the member’s surviving spouse for life. If there is no surviving spouse entitled to an allowance under this

section or if the surviving spouse dies before every child of the deceased member attains the age of years, then the allowance that the surviving spouse would have received had the surviving spouse lived, shall be paid to the surviving spouse’s child or children under that age, collectively, to continue until each child dies or attains that age. However, no child may receive any allowance after marrying or attaining the age of years. (

b) No allowance may be paid under this

section to a surviving spouse unless the surviving spouse was married to the member at least two years prior to the date of death and has attained the age of years on or prior to the date of death. (

c) Notwithstanding any other provisions of this section, the benefits otherwise payable to the children of the member shall be paid to the children up to the 22nd birthdays of the children if the children remain unmarried and are regularly enrolled as full-time students in an accredited school as determined by the board. (

d) No allowance may be paid pursuant to this

section to any person who is entitled to an allowance pursuant to

Section 31786. (

e) The superseding rights pursuant to this

section do not affect benefits payable to a named beneficiary as provided under

Section 31789, 31789.01, 31789.1, 31789.12, 31789.13, 31789.2, 31789.3, 31789.5, or 31790. (

f) This

section is not applicable in any county until the board of retirement, by resolution adopted by a majority vote, makes this

section applicable in the county. The board’s resolution may designate a date, which may be prior or subsequent to the date of the resolution, as of which the resolution and this

section shall be operative in the county.