The statement that best describes a cause of increased consumption of goods in the U.S. post-WWII is:
U.S. citizens had saved money during WWII and were eager to spend it.
This reflects the pent-up demand and savings that many Americans had accumulated during the war years when consumer goods were scarce due to rationing and production focus on the war effort. After the war, there was a burst of consumer spending as people sought to purchase goods they had been unable to buy previously.