; and (ii) transmit in writing to the person who produced such material, answers, or testimony notice of the identity and address of the successor so designated. (B) Successor Any person who is designated to be a successor under this paragraph shall have, with regard to such material, answers, or transcripts, the same duties and responsibilities as were imposed by this section upon that person’s predecessor in office, except that the successor shall not be held responsible for any default or dereliction which occurred before that designation. (k) Judicial proceedings (1) Petition for enforcement Whenever any person fails to comply with any civil investigative demand issued under subsection (a), or whenever satisfactory copying or reproduction of any material requested in such demand cannot be done and such person refuses to surrender such material, the Attorney General may file, in the district court of the United States for any judicial district in which such person resides, is found, or transacts business, and serve upon such person a petition for an order of such court for the enforcement of the civil investigative demand. (2) Petition to modify or set aside demand (A) In general Any person who has received a civil investigative demand issued under subsection (a) may file, in the district court of the United States for the judicial district within which such person resides, is found, or transacts business, and serve upon the investigator identified in such demand a petition for an order of the court to modify or set aside such demand. In the case of a petition addressed to an express demand for any product of discovery, a petition to modify or set aside such demand may be brought only in the district court of the United States for the judicial district in which the proceeding in which such discovery was obtained is or was last pending. Any petition under this subparagraph must be filed— (i) within 20 days after the date of service of the civil investigative demand, or at any time before the return date