; or (B) in the case of a person other than a natural person, a person having knowledge of the facts and circumstances relating to such production and authorized to act on behalf of such person, to the effect that all of the documentary material required by the demand and in the possession, custody, or control of the person to whom the demand is directed has been produced and made available to the custodian. (2) Production of materials Any person upon whom any civil investigative demand for the production of documentary material has been served under this section shall make such material available for inspection and copying to the investigator identified in such demand at the principal place of business of such person, or at such other place as the investigator and the person thereafter may agree and prescribe in writing, or as the court may direct under subsection (k)(1). Such material shall be made so available on the return date specified in such demand, or on such later date as the investigator may prescribe in writing. Such person may, upon written agreement between the person and the investigator, substitute copies for originals of all or any part of such material. (h) Interrogatories (1) Answers Each interrogatory in a civil investigative demand served pursuant to this section shall be answered separately and fully in writing under oath, and it shall be submitted under a sworn certificate, in such form as the demand designates, by— (A) in the case of a natural person, the person to whom the demand is directed