; (B) submit such tangible things; (C) file written reports or answers to questions; (D) give oral testimony concerning documentary material, tangible things, or other information; or (E) furnish any combination of such material, answers, or testimony. (2) Requirements Each civil investigative demand shall state the nature of the conduct constituting the alleged violation which is under investigation and the provision of law applicable to such violation. (3) Production of documents Each civil investigative demand for the production of documentary material shall— (A) describe each class of documentary material to be produced under the demand with such definiteness and certainty as to permit such material to be fairly identified; (B) prescribe a return date or dates which will provide a reasonable period of time within which the material so demanded may be assembled and made available for inspection and copying or reproduction; and (C) identify the custodian to whom such material shall be made available. (4) Production of things Each civil investigative demand for the submission of tangible things shall— (A) describe each class of tangible things to be submitted under the demand with such definiteness and certainty as to permit such things to be fairly identified; (B) prescribe a return date or dates which will provide a reasonable period of time within which the things so demanded may be assembled and submitted; and (C) identify the custodian to whom such things shall be submitted. (5) Demand for written reports or answers Each civil investigative demand for written reports or answers to questions shall— (A) propound with definiteness and certainty the reports to be produced or the questions to be answered; (B) prescribe a date or dates at which time written reports or answers to questions shall be submitted