; (B) prescribe a date or dates at which time written reports or answers to questions shall be submitted; and (C) identify the custodian to whom such reports or answers shall be submitted. (6) Oral testimony Each civil investigative demand for the giving of oral testimony shall— (A) prescribe a date, time, and place at which oral testimony shall be commenced; and (B) identify an Agency investigator who shall conduct the investigation and the custodian to whom the transcript of such investigation shall be submitted. (7) Service Any civil investigative demand issued, and any enforcement petition filed, under this section may be served— (A) by any Agency investigator at any place within the territorial jurisdiction of any court of the United States; and (B) upon any person who is not found within the territorial jurisdiction of any court of the United States— (i) in such manner as the Federal Rules of Civil Procedure prescribe for service in a foreign nation; and (ii) to the extent that the courts of the United States have authority to assert jurisdiction over such person, consistent with due process, the United States District Court for the District of Columbia shall have the same jurisdiction to take any action respecting compliance with this section by such person that such district court would have if such person were personally within the jurisdiction of such district court. (8) Method of service Service of any civil investigative demand or any enforcement petition filed under this section may be made upon a person by— (A) delivering a duly executed copy of such demand or petition to the individual or to any partner, executive officer, managing agent, or general agent of such person, or to any agent of such person authorized by appointment or by law to receive service of process on behalf of such person; (B) delivering a duly executed copy of such demand or petition to the principal office or place of business of the person to be served