A conflict arises between two kindergarten children while the teacher is busy in another area. Out of frustration, one child hits the other. What do you do?

A. Address the behavior because it's unacceptable.
B. Encourage the other to hit back so he or she won't do it again.
C. Send them to the hallway so other children don't see them fight.
D. Ignore them so they will learn to resolve the problem on their own.