Reality is often quite different, a great national striving consisting frequently of failure. Many of the oft-told stories of the most pluralistic nation on earth are stories not of tolerance, but of bigotry. Slavery and sweatshops, the burning of crosses and the ostracism of the other. Children learn in social-studies class and in the news of the lynching of blacks, the denial of rights to women, the murders of gay men. It is difficult to know how to convince them that this amounts to "crown thy good with brotherhood," that amid all the failures is something spectacularly successful. Which statement best summarizes the central idea of this excerpt?

Due to the many cultures represented in our nation, our history is spoiled by racist acts.
The high number of horrors committed in our diverse nation makes it difficult to believe in a united people.
Children in American schools are only learning about the negative parts of American history—and none of the positive.
Among all of the acts of hatred and racism, there is good in our population made of immigrants.