Select the plot element that is not part of the plot structure of a story

Which of the following is NOT part of the plot structure? The cast of characters are NOT part of the plot structure. The plot structure consists of an exposition, a rising action, a climax, falling action, and the resolution. Characters are important to the plot, but not a part of the actual structure of it.

i think its descriptve symbols but im not sure

edwards uses the phrase "o who can express what the state of a soul in such circumstances is! " in order to illustrate that this type of suffering is unimaginable. the word "express" denoted that the state of a suffering soul is required to be described by any person, but it would not happen because no one can imagine how this suffering is felt.  

-show what might happen if the reader disobeys edwards is not correct because this is described trhough the text, not by the phrase used.

-describe what endless suffering looks and feels like is not correct because this description might be the porpuse of the excerpt provided, not the porpuse of using the phrase during the writting.

-prove that few people have survived limitless suffering is not correct because it is implied that the soul of a person is already suffering and doesn't have any way to escape.