For each of the following examples, indicate which of these terms apply. (Some terms may apply more than once—others might not apply at all.) The terms are:

Fixed responsiveness of input Proportional responsiveness of input Variable cost Fixed cost Step cost Mixed cost A for-profit school provides classes of instruction. This requires it to have instructors, classrooms, and textbooks. It rents the classrooms. It also has a principal overseeing the school. Up to 25 students can be taught in a single room, but one instructor. Each student needs their own textbook. Which term applies to:

A. The number of textbooks?

B. The cost of the textbooks?
C. The number of teachers?
D. The cost of the teachers?
E. The number of principals?
F. The cost of the principal?
G. The overall cost of the school?