In the consumer culture of the 1920s, a) people purchased nonessential goods on a regular basis. b) people purchased only essential goods on a regular basis. c) people reduced their purchasing of essential goods. d) people reduced their purchasing of nonessential goods. (incorrect: b and d)

In the consumer culture of the 1920s, A. people purchased nonessential goods on a regular basis.
This was a time of prosperity after WWI, in which America became richer than before because it was selling a lot of its weaponry to other countries which were participating in the war. This was also a time before the Great Depression, so people were still rich and had enough money to spend on anything, be it essential or nonessential, which they did at the time in abundance. 

Answer must be C .