I believe it’s sometimes because it describes an adjective
Montresor gets revenge on his friend fortunato since he criticized him;he buried fortunato behind a wall
To me the entire speech is sort of an optimistic tone.
The supporting details are used when you want to explain, describe, illustrate the main idea of what you are saying or writing. Details can be facts, definitions, quotations, more information or examples. These details must be important, significant in order to help to develop the central idea of your speech. With this explained, the right answer is <em>C, meaning of words</em>. The other ones are relevant and useful to explain the main idea.