Tommy finding the idea of a human teacher strange shows what?

Correct answer: Machine teachers have become normal in his time

The governing idea is the effect of historical perspective on a person’s understanding of education. Tommy has grown up in a future society where children are taught individually by mechanical teachers at home. Because this system is ordinary to him, he finds the old idea of a human teacher unusual and asks questions about it. Option A is correct: his surprise shows that machine-based education has become normal in his time. Option B is too broad and false, because he knows about teachers as a concept. Option C contradicts the old book, which describes schools from the past. Option D is absurd and unsupported; the story presents human teachers as active speakers and instructors.