What is the key difference between a theme and a central idea?

Read the excerpt from "i wandered lonely as a cloud." for oft, when on my couch i lie in vacant or in pensive mood, they flash upon that inward eye which is the bliss of solitude; and then my heart with pleasure fills, and dances with the daffodils. which statement best describes the lines that are underlined in this excerpt? both lines contain alliteration, which creates a cheerful tone. both lines contain alliteration, which draws attention to the speaker's feelings. the lines use rhyme to transition from deep thought to a joyful memory. the lines use rhyme to show the speaker's feelings of isolation.