(a) Notwithstanding Section 31492, each monthly survivor allowance paid pursuant to subdivision (a) of Section 31492 on account of a member who retires on or after the operative date of this section shall be equal to 55 percent of the retirement pension, if not modified in accordance with the optional survivor allowance in subdivision (c) or (d) of that section.
(b) This section is only applicable to Los Angeles County and is not operative until the board of supervisors of that county elects, by resolution adopted by a majority vote, to make this section operative in the county.