In the short story 'The Gift of the Magi' by O. Henry, a young couple, Jim and Della, are deeply in love but very poor. Each wants to buy a special Christmas gift for the other. Della has only $1.87 to spend, while Jim has sold his prized possession, a watch, to buy a gift for Della. The story emphasizes themes of love and sacrifice.
Which of the following details best supports the theme of love and sacrifice in the story?