a futuristic novel tells the story of the united states after a nuclear disaster. people live separately in underground bunkers, where they cannot contact those in different bunkers. civilization survives for many generations, but each isolated group developed differently. while some people are still able to find a degree of happiness, others suffer under cruel dictators or live in terrible conditions. without any awareness of the other survivors, each group had to make do without important goods and abilities, and those who suffer have no idea that life could be better. which is the best statement of the theme of the story