Explanation 2
Why was the response "On the third test" the best choice?
→ On the third test, Mrs. Johnson started having suspicions of student cheating. However, she gave the class the benefit of the doubt. Doing this and not addressing the issue, made students feel they can continue with this improper behavior, which resulted in cheating on the fourth test. Therefore, Mrs. Johnson began losing classroom management around the third test, when students started to experiment with cheating.