Although the options are not included in this question, one of the ideas that could best serve as a theme in the story "The Gift of the Magi" is that of self-sacrifice. In this story, both Della and Jim sacrifice something that they really value in order to give a gift to the other one. More importantly, this gift is not important because of its material worth but because it is a sign of their love for each other. O. Henry conveys the idea that true love is impossible without some sacrifice.
