In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
Q: What quality do effective disciplinarians in the classroom need?, Context: A modern example of school discipline in North America and Western Europe relies upon the idea of an assertive teacher who is prepared to impose their will upon a class. Positive reinforcement is balanced with immediate and fair punishment for misbehavior and firm, clear boundaries define what is appropriate and inappropriate behavior. Teachers are expected to respect their students; sarcasm and attempts to humiliate pupils are seen as falling outside of what constitutes reasonable discipline.[verification needed]
A: 
assertive