Why is there a lack in the machine teacher despite lessons and checking?

Because it lacks empathetic understanding and lively interaction

The governing concept is the difference between mechanical efficiency and human teaching. The machine teacher can display lessons, give exercises, and inspect answers, so its lack is not a failure to perform those technical functions. What it cannot provide is empathy, flexible human conversation, encouragement, and an understanding of a learner's feelings or confusion. Margie's dissatisfaction comes from this emotional and social gap, not from the absence of instruction. Option A is correct because it identifies the missing human qualities. Options B and C are contradicted by the story, since the machine asks work and teaches lessons. Option D is plainly false because the machine is installed in Margie's home.

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