Read this excerpt from "The Destructors" by Graham Greene and answer the question that follows: "Blackie lumbered nearer the saw and the sledge-hammer. Perhaps after all nobody had turned up; the plan had been a wild invention; they had woken wiser. But when he came close to the back door he could hear a confusion of sound hardly louder than a hive in swarm; a clickety-clack, a bang bang bang, a scraping, a creaking, a sudden painful crack. He thought; it’s true, and whistled." Why is confusion an effective choice?