Answer:
d. the Civil War
Step-by-step explanation:
The American Civil War was very influential for the creation of literature belonging to the movement known as realism. This is because the war caused a lot of destruction, deaths, sadness and changed the entire social, political and economic structure of the country. in this way, as the reality proved to be difficult and tenebrous, the American writers no longer wanted to rely on fantastical and romantic illusions, but preferred to show the terrors they were experiencing and all the complexity of the current moment.
The American civil war was the armed conflict that sought to separate the southern states from the American territory, forming another country, in addition to seeking to solve the problems surrounding slavery.