The correct asnwer to this question is 1 3 and 4 or
It shed light on the benefits of slavery.
It ignored the unique cultures of different regions of the country
It mirrored the somberness of postwar America with a new realism.
It would be past tense because when you say something occurred you are saying that it has already happened
An author can try to give the thoughts of the character or maybe a flashback from the past that reader doesn’t know about yet.