Answer:
The noun 'rippulous' helps the reader 'hear' the pond.
Step-by-step explanation:
The Lorax is a children's fiction witten by Dr. Seuss. The book speaks about the plight of our environment.
The imagery is a literary device used by the writer to appeal to the sense of sight of the readers. Through the lens of thsi rhetoric, the readers are able to see what the narrator sees.
So, the diction that affects the imagery is the word 'rippulous' helps the reader to 'hear' the pond. The word 'rippulous' appeals to the sense of sight of the readers, and enables them to hear the sound that ripples make in a pond.
Thus the last option is the correct answer.