Keynesian Economists Believed That the Prolonged Unemployment of the 1930s

Multiple Choice

Keynesian economists believed that the prolonged unemployment of the 1930s was the result of

A) the sharp reduction in the supply of money during 1929-1933 and another monetary contraction in 1938.
B) the high interest rates of the 1930s.
C) the double-digit inflation of the 1930s.
D) insufficient aggregate demand and the failure of market forces to direct the  economy back to full employment.