income) constitute income to it in such year, such taxpayer may, at its election made in its return for any taxable year, treat such increase as income received in such taxable year. If any such election is made with respect to any such obligation, it shall apply also to all such obligations owned by the taxpayer at the beginning of the first taxable year to which it applies and to all such obligations thereafter acquired by it and shall be binding for all subsequent taxable years, unless on application by the taxpayer the Franchise Tax Board permits it, subject to such conditions as the Franchise Tax Board deems necessary, to change to a different method.

a territory, or a possession of the United States, or any political subdivision of any of the foregoing, or of the District of Columbia,

which is issued on a discount basis and payable without interest at a fixed maturity date not exceeding one year from the date of issue, the amount of discount at which such obligation is originally sold shall not be considered to accrue until the date on which such obligation is paid at maturity, sold, or otherwise disposed of.