What change is shown by the printed book becoming rare in future education?

Correct answer: The medium of knowledge has moved from physical pages to digital screens

The governing concept is the transformation of the medium through which knowledge is stored and accessed. In the story’s future, telebooks and screen-based lessons are normal, while an old paper book is unusual enough to attract Margie and Tommy’s attention. Knowledge has not disappeared; rather, its physical form and the habits connected with reading have changed. Digital technology makes information available through mechanical teachers and electronic displays instead of printed pages. Therefore, option C is correct. Option A concerns appearance, not educational change; option B is unsupported; and option D is absurd because the children continue to receive lessons and information.