What is the root cause of the problem in future education in the story?

Correct answer: Education being cut off from human community

The governing concept is social isolation in an education system that has become almost entirely mechanical and private. Margie studies alone in a room at home, receives lessons from a machine, and has no classmates with whom she can compare ideas or share ordinary school experiences. Her difficulty with Geography is only a symptom of the arrangement, not its root cause; the mechanical teacher can be repaired and adjusted. The diary and the yellow appearance of the old book are incidental details that do not create the educational problem. Option A is therefore correct because it identifies the deeper disconnection between learning and human community. The story does not condemn every machine; it questions a system that removes companionship, dialogue, and personal interaction from education.