What does it mean to say a visual aid should "serve a purpose"?

15 points & brainliest ! when the speaker compares dream memories to fall leaves that are hard to catch, what feelings does this simile suggest? what was i dreaming? it's coming back to me! but scraps of dream memories drift just out of reach like fall leaves dancing in the wind that i chase madly but cannot catch. a. the speaker is confident b. the speaker is disappointed. c. the speaker is ashamed. d. the speaker is excited. i am stuck between b & d. explain your answer