(A) ** Warren G. Harding
(B) Calvin Coolidge
(C) Herbert Hoover
(D) Franklin Roosevelt
EXPLANATIONS BELOW
Concept note-1: -The main reasons for America’s economic boom in the 1920s were technological progress which led to the mass production of goods, the electrification of America, new mass marketing techniques, the availability of cheap credit and increased employment which, in turn, created a huge amount of consumers.
Concept note-2: -The Steel Strike of 1919 became the focal point for profound social anxieties, especially fears of Bolshevism. Organized labor had grown in strength during the course of the war. Many unions won recognition, and the 12-hour workday was abolished.
Concept note-3: -The war gave the USA high productivity and high employment rates with good wages for workers. Many industries began to apply the principles of mass production during the war, making their factories more efficient. When the war ended, they were in a good position to produce goods quickly and cheaply.