Except as provided in subsection (b), gross income does not include interest on any State or local bond.
Any private activity bond which is not a qualified bond (within the meaning of section 141).
Any arbitrage bond (within the meaning of section 148).
Any bond unless such bond meets the applicable requirements of section 149.
The term "State or local bond" means an obligation of a State or political subdivision thereof.
The term "State" includes the District of Columbia and any possession of the United States.