I think your answer would be C. A lesson about life. Most short stories teach something to the readers.
The best meaning to life is " Beings "
Jack (Earnest) Worthing is a man approximately in his late 20's or early 30's, presumably an orphan, and the guardian of a niece which is related to the man who adopted him after finding him inside a handbag at Victoria Station.
As it was, his protector was a rich man, and Jack enjoys a home in the country (where his name is Jack) and a place in the city, where he goes to entertain himself.