N.C. Gen. Stat. § 115C-85
When the State Board of Education has adopted, upon the recommendation of the Superintendent of Public Instruction, a standard course of study at each instructional level in the elementary school and the secondary school, setting forth what subjects shall be taught at each level, it shall proceed to select and adopt textbooks.
As used in this part, "textbook" means systematically organized material comprehensive enough to cover the primary objectives outlined in the standard course of study for a grade or course. Formats for textbooks may be print or nonprint, including hardbound books, softbound books, activity-oriented programs, classroom kits, and technology-based programs that require the use of electronic equipment in order to be used in the learning process.
Textbooks adopted in accordance with the provisions of this Part shall be used by the public schools of the State except as provided in G.S. 115C-98(b1).
N.C. Gen. Stat. § 115C-85