It shall be presumed, for the purposes of this part, that all beer removed from the internal revenue bonded premises of a beer manufacturer has been sold in this State by the manufacturer, unless one of the following is proved to the satisfaction of the board, in reports on forms prescribed by the board:
(a) That the beer has been sold and delivered in internal revenue bond to another beer manufacturer in this State.
(b) That the beer has been exported without this State or sold for export by the beer manufacturer making the report and actually exported from this State.
(c) That the beer is beer otherwise exempted from taxation under this part.