Answer:
Dickens maintains a cheerful tone showing Scrooge's redemption and how he promoted good at the end of the story and celebrated Christmas with those who care about him.
Explanation:
"A christimas Carol" is a very dark story for Christmas, as it deals with death, haunt, avarice, despair and regret. However, Dickens did not want the joy of Christmas and the feeling of comfort of that date to be dissipated from history and maintains a cheerful tone when he shows scrooge regretting everything he had done, promoting good, celebrating and being happy in the end.
