(a) Any member in Group 1 shall be eligible for early service retirement upon satisfying one (1) of the following:
(1) Attainment of fifty-five (55) years of age with the applicable years of creditable service as set forth in § 8-36-204; or
(2) At any age less than fifty-five (55) years of age with twenty-five (25) years of creditable service; provided, that this provision shall be optional for political subdivisions participating under chapter 35 of this title.
(b) Any member in Group 2 shall be eligible for early retirement upon satisfying one (1) of the following:
(1) Attainment of fifty-five (55) years of age with ten (10) years of creditable service; or
(2) If the member is employed by a political subdivision which has not authorized unreduced service retirement benefits pursuant to § 8-36-201(b)(1)(B), at any age with thirty (30) years of creditable service.
(c) Any member in Group 3 shall be eligible for early service retirement upon attaining fifty-five (55) years of age with eight (8) years of service.