Macroeconomic theory that emphasised the theories of Keynes and deemphasised the Classical theory developed as the result of the failure of?

(A) economic theory to explain the simultaneous increases in inflation and unemployment during the 1970s.
(B) fine tuning during the 1960s.
(C) the economy to grow at a rapid rate during the 1950s.
(D) the Classical model to explain the prolonged existence of high unemployment during the Great Depression.