In Three of the Following Situations,ignoring a Student's Misbehavior Might

In three of the following situations,ignoring a student's misbehavior might be the best approach to take. Considering the textbook's discussion of this strategy,in which situation would ignoring not be advisable?

A) Anita has whispered a juicy (and apparently very amusing) piece of gossip to her friend,who in turn is passing it along to two others.
B) Bill breaks a beaker and seems very remorseful that he has done so; he vows to be more careful in the future.
C) Cathy is usually very attentive in class,but today when the teacher asks her a question,it's clear that she hasn't been listening.
D) An entire class is excited about their spring break that starts tomorrow.