Why do old-time children appear happy in Margie's imagination while studying?

Correct answer: Because they studied with a human teacher and classmates

The governing concept is the contrast between isolated machine-based education and shared human education. Margie studies alone at home with a mechanical teacher, so learning feels fixed, impersonal and sometimes unpleasant. When Tommy tells her about old schools, she imagines children sitting together, learning from a human teacher and interacting with classmates. Their happiness does not mean that they had no lessons or that school was only a playground. Rather, companionship, discussion, encouragement and a teacher’s personal attention made study a lively social experience. Therefore, option C is correct; options A, B and D misunderstand the reason for the children’s apparent joy.