Which of the following is NOT an allowable purchase for textbook money?

Teacher guides are generally considered supplementary materials that assist educators in delivering instruction rather than direct instructional materials for students. In many educational funding guidelines, including those that pertain to the use of textbook money, allowable purchases typically focus on items that are directly utilized by students, such as student textbooks, workbooks, and even supplemental resources that enhance students' learning experiences. Since teacher guides do not fall into the category of student-directed educational materials, they are often classified as non-allowable expenses when it comes to textbook funding. This delineation helps ensure that funds are used to support direct student learning materials, ensuring that they are effectively utilized in the classroom setting.