Actually there are some exceptions in some cases though: a/an
example: "not only is there 3 species, but there is a 4th specimen."
Answer:
B. Optional
Explanation:
A comma can be defined as a punctuation mark that is typically used for indicating a break in elements of a series or list in a sentence. Also, it's used to indicate the shortest pause in a sentence.
In the English language, conjunction can be defined as an English word that is typically used for connecting two or more clauses, words, phrases, or sentences. Some examples of conjunction are but, and, although, because, or, yet, etc.
When there are three or more items (elements) in a series, the final comma before the conjunction (and, or, nor) is optional.
I wanna say Kerala but I’m not sure
Edgar Allan Poe's "The Cask of Amontillado" presents an excellent example of his stylistic originality through its mood and tone. From the opening sentences, Poe sets an anxious and suspenseful tone by right away pulling the reader into Montresor's vengeful obsession. This creates an air of tension as the story builds toward its climax, which Poe contrasts with satiric humor. He also sustains a mood of eerie foreboding throughout the story by using many overt symbols of death and decay.
