According to Keynes,lengthy recessions can occur because

A) nominal wages fall rapidly when there is a decrease in aggregate demand,which leaves workers with less income to spend.
B) the stock market tends to overreact to economic forecasts.
C) there is significant downward rigidity in prices and wages.
D) None of the choices are correct.

According to Keynes, lengthy recessions can occur because there is significant downward rigidity in prices and wages. This means that prices and wages do not adjust quickly to changes in aggregate demand, which can prolong recessions. Option A is not entirely correct, as Keynes did not believe that nominal wages fall rapidly during a recession. Option B is not correct, as the stock market is not a significant factor in Keynesian economics. Option D is not correct, as there is a correct choice.