What Was John Maynard Keynes's Primary Message Concerning Recessions and Depressions

What was John Maynard Keynes's primary message concerning recessions and depressions?

A) Governments should not intervene in the economy but leave the economy to recover of its own accord from a recession or depression.
B) Recessions and depressions can occur as a result of inadequate aggregate demand for goods and services.
C) Long-run policy intervention by governments is needed to avoid recessions and depressions.
D) Recessions and depressions are entirely monetary phenomena.