(a) Proof of the claimant's date of birth must be established by the submission of any of the following:

(1) Birth certificate;

(2) Baptismal certificate;

(3) Tribal records; or

(4) Hospital records of birth.

(b) Absent any indication to the contrary, the Program will assume that the earliest date within the designated time period indicated on any records accepted by the Program as proof of the claimant's physical presence in the affected area or participation during a period of atmospheric nuclear testing was also the date of initial exposure.