The boy said ____ when his mother scolded him.

The correct answer is: Sorry

Sorry is the word used to put down the dispute arouse. The mother is scolding him and by acknowledging the mistake he apologizes his mistake and asks sorry. By asking sorry, it means that the mistake should not be repeated again. By uttering that word, one feels for the mistake done and regrets. The guilt feeling is felt by the victim and he should realize his mistake and ask sorry from the depth of the heart.