The correct answer is: "booming—thanks to unharmed industry that quickly shifted to production of consumer goods".
After World War I, the United States became the more proficient economy in the World. Many European countries, whose economies had been devastated by the huge costs of the war (regardless of who won), were indebted with the U.S. - this led to a bigger money flow that was smartly used in the production of consumer goods and the advertising of these products, to stimulate the constant demand by the population.