A stated theme in literature is a central topic, subject, or message that the author is presenting for us to ponder, and it is expressed directly in the text. Out of the options you provided, “The Gift of the Magi” by O. Henry is the clearest example of a stated theme in literature. The story’s theme is explicitly stated in the title and revolves around the idea of selflessness and sacrifice. The story explores how love can inspire people to make great sacrifices for one another, even if it means giving up something they hold dear.
I hope this helps answer your question!