The Board may ask for evidence to prove where the employee had a permanent home at the time of filing an application or, if earlier, at the time the employee died if--
(a) The claimant is applying for payments as the employee's wife, husband, widow, widower, parent, or child; and
(b) The claimant's relationship to the employee depends upon the laws of the state where the employee had his or her permanent home when his or her wife or husband applied for an annuity or when the employee died.