Can you guys please sum this up for me ?

How did the roaring 20s mark the end of the progressive era? a. mass production reduced wealth disparity and turned public opinion pro business b. labor unions won big legislative gains in workers rights and disbanded c. public officials cut taxes on businesses and reduced spending on services d. america increasing influence in world affairs redirected public attention to foreign policy

What is the main idea of this excerpt? 1.1.3

How did the results of wwi benefit the u.s.?