An ellipsis is most often used to do which of the following? Select one:
to illustrate main ideas and key points
to mark the intentional omission of words
O
to emphasize important details
O
to add parenthetical information

B.

Explanation:

An ellipsis, in punctuation, is a series of three dots (...) which is used to mark that some word or words are intentionally omitted from a sentence. An ellipsis is used by adding space on each side of the ellipsis when surrounded by words, except when it is used adjacent to quotation marks. In informal form of writing, it is used to suggest hesitation, or dwindling from thoughts.

Therefore, the correct answer is that an ellipsis is used to mark intentional omission of words, line, phrases, etc in a sentence.

Thus option B is correct.

the words “strangest” and “unusual” suggest that the narrator is about to tell the story of an odd or puzzling group of people.

i may be wrong but i think your answer is flashback