The "Star Trek<span>" </span>effect<span> is the cultural </span>impact<span> that the television show has had on societies where it has been shown regularly since the 1960s. ... But </span>Star Trek<span> was the first television series aimed at adults to tell sophisticated morality tales</span>
The part of Ernest Hemingway's short story "The End of Something" that is the best example of rejection of traditional beliefs is C. when Nick says love is not fun.
The traditional belief would suggest otherwise - however, by denying the thrill of love, Nick is getting rid of this innate traditional belief. The other examples do not really show this type of rejection, they represent other things that can be found in the story.
The answer to your question would be, “to show that despite its differences, America is still a country that unites in times of strife.” Hope this helps!:)