What kind of turn does finding the old book bring in the plot?

Correct answer: It starts the comparison of old and new education systems

The governing narrative concept is the turning point: an object can introduce a new conflict or comparison and redirect the reader's attention. Tommy's discovery of the old printed book changes the conversation from Margie's routine mechanical lessons to the unfamiliar system of schools from the past. The children compare printed pages with telebooks, human teachers with mechanical teachers, and group classrooms with solitary home study. Thus option A is correct because the book launches the central comparison on which both the plot and theme depend. Option B is false because Margie continues studying; option C is impossible within the story; and option D confuses Tommy with the County Inspector, who is an adult technician.