The correct answer is B.
The Keynesian theory supports that the economic authorities intervene the markets to stimulate the demand and help the economy to recover more quickly, in addition, to avoid the unemployment, that usually is the worst consequence of the economic crises.
On the other hand, classical economists like Smith, criticize the Keynesians, because they claim that the intervention of economic authorities is a distortion which makes that markets do not find their point of equilibrium, because in the long term it causes inflation.