N.D. Cent. Code § 61-07-25
Any person interested in the district or in the issue or sale of the bonds may answer the petition. The provisions of title 28 and the North Dakota Rules of Civil Procedure relating to the answer to a complaint shall be applicable to an answer to a petition. The person answering the petition shall be the defendant in the special proceeding and the board shall be the plaintiff. Every material statement of the petition not specifically controverted by the answer, for the purpose of such special proceeding, shall be taken as true. Each person failing to answer the petition shall be deemed to admit as true all the material statements of the petition. The rules of pleading and practice provided by title 28 and the North Dakota Rules of Civil Procedure which are not inconsistent with the provisions of this chapter are applicable to the special proceeding provided for in this chapter.
N.D.C.C. § 61-07-25