Description is the following theme of a literary work.
Explanation:
1) Making a reader imagine the things that is written is called descriptive writing which is a literary device that enhances a reader to have a picture or vision to the story. It describes a place, a person or thing in a way of a picture for the reader.
2) And in this passage from "The Life You Save May Be Your Own" by Flannery O'Connor is of a descriptive writing.
The old woman first slid to the edge of her chair, based on the passage.
3) The example of rhyme scheme for a rhyming couplet is
d. aa