(a) Availability; procedures for use. Any party may serve upon any other party written interrogatories to be answered by the party served or, if the party served is a public or private corporation or a partnership or association or governmental agency, by any officer or agent, who shall furnish such information as is available to the party. Interrogatories may, without leave of the Presiding Officer, be served upon any party after filing of the answer.

(b) Procedures for response. Each interrogatory shall be answered separately and fully in writing under oath, unless it is objected to, in which event the reasons for objection shall be stated in lieu of an answer. The answers are to be signed by a responsible representative of the respondent and the objections signed by the representative making them. The party upon whom the interrogatories have been served shall serve a copy of the answers, and objections if any, within 30 days after service of the interrogatories. The Presiding Officer may allow a shorter or longer time for response. The party submitting the interrogatories may move for an order under §511.36 with respect to any objection to or other failure to answer an interrogatory.

(c) Scope of interrogatories. Interrogatories may relate to any matters which can be inquired into under §511.31(c)(1), and the answers may be used to the extent permitted under this part. An interrogatory otherwise proper is not objectionable merely because an answer to the interrogatory would involve an opinion or contention that relates to fact or to the application of law to fact, but the Presiding Officer may order that such an interrogatory need not be answered until a later time.

(d) Option to produce business records. Where the answer to an interrogatory may be derived or ascertained from the business records of the party upon whom the interrogatory has been served, or from an examination, audit or inspection of such business records, or from a compilation, abstract or summary based thereon, and the burden of deriving the answer is substantially the same for the party serving the interrogatory as for the party served, it is a sufficient answer to the interrogatory to specify the records from which the answer may be derived or ascertained and to afford to the party serving the interrogatory reasonable opportunity to examine, audit or inspect such records and to make copies, complications, abstracts, or summaries.