When we hear the phrase 'once upon a time,' we know a story is about ... Learn what sequence words are and how to use them,

a story is about to Begin

"once upon a time" is an example of the use of sequence words

Explanation:

When we hear the phrase "once upon a time" we know that a story is about to Begin. and This phrase is an example of a sequence of words .

Sequence words are used to mainly organize a story so that the reader can understand the events that occurred in the story . examples of such words include : "then" , "when" "later"  and so on

for the comment!

i feel like it is actually b.