(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 court, be served upon the plaintiff after the summons and a copy of the complaint are served upon the defendant, or the complaint is filed, whichever shall first occur, and upon any other party with or after service of the summons and complaint upon that party.

Interrogatories shall be so arranged that after each separate question there shall appear a blank space reasonably calculated to enable the answering party to place the written response. In the event the responding party either chooses to place the response on a separate page or pages or must do so in order to complete the response, the responding party shall clearly denote the number of the question to which the response relates, including the subpart thereof if applicable. 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 the person making them, and the objections signed by the attorney 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 the service of the interrogatories, except that a defendant may serve answers or objections within 40 days after service of the summons and complaint upon that defendant. The parties may stipulate or any party may move for an order under rule 37(a) with respect to any objection to or other failure to answer an interrogatory.

(b) Scope; Use at Trial. Interrogatories may relate to any matters which can be inquired into under rule 26(b), and the answers may be used to the extent permitted by the Rules of Evidence.

An interrogatory otherwise proper is not necessarily objectionable merely because an answer to the interrogatory involves an opinion or contention that relates to fact or the application of law to fact, but the court may order that such an interrogatory need not be answered until after designated discovery has been completed or until a pretrial conference or other later time.

An interrogatory otherwise proper is not objectionable merely because the propounding party may have other access to the requested information or has the burden of proof on the subject matter of the interrogatory at trial.

(c) Option To Produce Business Records. Where the answer to an interrogatory may be derived or ascertained from the business records, including electronically stored information, 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 or ascertaining the answer is substantially the same for the party serving the interrogatory as for the party served, it is sufficient answer to such 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, compilations, abstracts or summaries. A specification shall be in sufficient detail to permit the interrogating party to locate and to identify, as readily as can the party served, the records from which the answer may be ascertained.