`(C)(i) the manufacture for, transfer to, or possession by, the United States or a State or a department or agency of the United States, or a State or a department, agency, or political subdivision of a State, of a junk gun; or
`(ii) the transfer to, or possession by, a law enforcement officer employed by an entity referred to in clause (i) of a junk gun for law enforcement purposes (whether on or off-duty);
`(D) the transfer to, or possession by, a rail police officer employed by a rail carrier and certified or commissioned as a police officer under the laws of a State of a junk gun for purposes of law enforcement (whether on or off-duty); or
`(ii) the transfer to, or possession by, a law enforcement officer employed by an entity referred to in clause (i) of a junk gun for law enforcement purposes (whether on or off-duty);
`(D) the transfer to, or possession by, a rail police officer employed by a rail carrier and certified or commissioned as a police officer under the laws of a State of a junk gun for purposes of law enforcement (whether on or off-duty); or