What is the most effective method to maintain discipline in the class?

Classroom-discipline theory in educational psychology separates PROACTIVE and REACTIVE strategies. A proactive strategy raises student engagement so that the boredom or disconnection which triggers most classroom misbehaviour never arises in the first place; a reactive strategy (punishment, exclusion, or escalation) only responds to disruption after it has already happened and leaves its underlying cause untouched.

Among the choices offered, only keeping teaching interesting and practical works this way: a lesson that holds attention and involves students in hands-on, real activity removes the very conditions — boredom, disengagement — that lead a class toward indiscipline, and a teacher can apply it in every lesson without singling anyone out.

• Removing indisciplined students from the class is exclusionary and reactive — it stops one incident but changes nothing about what happens in the lesson once the student returns, and it denies that student regular instruction.

• Informing guardians acts only after an incident, outside the classroom, and depends on someone else's response at home rather than giving the teacher a way to prevent disruption during the lesson.

• Extending special facilities to indisciplined students risks being read as a reward for the very behaviour a teacher is trying to reduce, and does not touch the instructional cause of the indiscipline.

So the standard, exam-recognised best practice for maintaining classroom discipline is the proactive one — engaging, practical teaching — rather than any of the reactive alternatives.