According to Keynesian economists, when the price level is constant, a downward shift in the aggregate expenditure curve is associated with

a. a rightward shift (increase) in the aggregate supply curve
b. a leftward shift (decrease) in the aggregate supply curve
c. a rightward shift (increase) in the aggregate supply curve
d. a leftward shift (decrease) in the aggregate supply curve
e. change in either the aggregate demand or aggregate supply curves

B