An election of any annuity under clause (1) or (2) of subsection (a), or any combination of annuities under subsection (b), shall provide that no deduction may be made from the elector’s retired or retainer pay after the last day of the month in which there is no beneficiary who would be eligible for the annuity if the elector died. For the purposes of the preceding sentence, a child (other than a child who is incapable of supporting himself because of a mental defect or physical incapacity existing before his eighteenth birthday) who is at least eighteen, but under twenty-three years of age, and who is not pursuing a course of study or training defined in
section 1435 of this title, shall be considered an eligible beneficiary unless the Secretary concerned approves an application submitted by the member under
section 1436(b)(4) of this title. An election of an annuity under clause (3) of subsection (a) shall provide that no deduction may be made from the elector’s retired or retainer pay after the last day of the month in which there is no eligible spouse because of death or divorce.