The Superintendent may at any time communicate to the Board that a particular book is unsatisfactory for the schools, whereupon the Board may call for a new selection and adoption. If the Board votes to change a textbook, it shall give the publisher 90 days' notice prior to May 1, after which it may adopt a new book or books on the subject for which a book is sought.
N.C. Gen. Stat. § 115C-92