the regulations at the time the contract was originally purchased, a divorce occurring after the original purchase and before the annuity payments commence under the contract will not affect the permissibility of the joint and survivor annuity benefits or other benefits under the contract, or require any adjustment to the amount or duration of benefits payable under the contract, provided that a qualified domestic relations order (within the meaning of section 414(p) of the Internal Revenue Code of 1986) or a divorce or separation instrument (within the meaning of section 71(b)(2) of the Internal Revenue Code of 1986)— (A) provides that the former spouse is entitled to the survivor benefits under the contract