The following individuals, if entitled to social security benefits, are paid such benefits by the Board:
(a) A railroad employee who has been credited with at least 120 months of railroad service;
(b) A wife or husband of a railroad employee who has been credited with at least 120 months of railroad service;
(c) A divorced wife or husband of a railroad employee who has been credited with at least 120 months of railroad service, but only if the divorced wife or husband is claiming social security benefits based upon the railroad employee's social security wages;
(d) A survivor of a railroad employee, including a surviving divorced spouse, remarried widow(er), surviving divorced mother or father, who is entitled, or upon application would be entitled, to an annuity under the Railroad Retirement Act;
(e) Any other person entitled to benefits under title II of the Social Security Act based on the social security wages of a railroad employee who has been credited with at least 120 months of railroad service, except survivors of a railroad employee when the Social Security Administration has jurisdiction for survivor benefits. See part 221 of this title.