((a)) Except as otherwise expressly provided by enactment of Congress, any offense against the United States begun in one district and completed in another, or committed in more than one district, may be inquired of and prosecuted in any district in which such offense was begun, continued, or completed.
((b)) Notwithstanding subsection (a), where an offense is described in section 7203 of the Internal Revenue Code of 1986, or where venue for prosecution of an offense described in section 7201 or 7206(1), (2), or (5) of such Code (whether or not the offense is also described in another provision of law) is based solely on a mailing to the Internal Revenue Service, and prosecution is begun in a judicial district other than the judicial district in which the defendant resides, he may upon motion filed in the district in which the prosecution is begun, elect to be tried in the district in which he was residing at the time the alleged offense was committed: , That the motion is filed within twenty days after arraignment of the defendant upon indictment or information.