What main difference becomes clear from comparing technology and old schools?

The difference between isolated machine study and collective classroom study

The governing concept is comparison between two models of education. Margie represents the future system, in which a child studies alone at home with a mechanical teacher, while the old school described in Tommy’s book brought children together in one classroom under a human teacher. Option D is correct because it captures the central difference: technological education is individualized and isolated, whereas traditional schooling is collective and socially interactive. The other options are factually wrong. Both systems include lessons, old schools certainly had children, and technology did not remove education; it changed its delivery, setting, and human relationships. The comparison explains why Margie finds old schools attractive.

This is a Class 9 English question. Chapter: The Fun They Had. Topic: impact of technology.