Final answer:
Option D, which compares the bell's sound to the Devil ringing a knell, is the best example of figurative language due to its use of simile and vivid imagery.
Step-by-step explanation:
The best example of figurative language in the passage is 'A sound as if with the Inchcape Bell, The Devil below was ringing his knell' (D). This sentence uses a simile by comparing the sound of the Inchcape Bell with the idea that the Devil is ringing a bell to signal the Rover's doom. It evokes a vivid image and implies a supernatural element to the Rover's impending death, making it a clear example of figurative language.