District retirement benefits program.

The retirement benefits program of the District shall consist of: (1) A defined benefit plan, as provided in 42 U.S.C. § 301 et seq. (“Social Security Act”); (2) An employee deferred compensation plan pursuant to § 457 of the Internal Revenue Code [26 U.S.C. § 457] governed by Chapter 36 of Title 47 ; (3) A defined contribution plan pursuant to § 401(a) of theInternal Revenue Code [26 U.S.C. § 401], for employer contributions on behalf of an employee pursuant to § 1-626.09(c) ; and (4) A defined contribution plan pursuant to section 401(a) of the Internal Revenue Code, for employer contributions on behalf of an employee pursuant to § 1-626.09(e) .