Which statement accurately compares America's post-World War I economy with Europe's?

A. Americans could invest in luxury goods like radios and automobiles, while European economies struggled to rebuild and grow.
B. America's democratic system made it easier and faster to rebuild after the war, while the monarchies and dictatorships in Europe operated far less efficiently.
C. The U.S. economic recovery was slowed by a huge number of refugees, while European countries closed their borders to outsiders.
D. The United States quickly adopted Keynesian economic policies, while Europeans refused to abandon traditional economic models.