Both the textbook and one of the lecture videos talked about the building blocks of the Keynesian perspective (also called the main features of the Keynesian perspective). Select them from the following list. a. Increased government spending is necessary to get out of a recession. b. Aggregate demand is very important. c. Aggregate demand is a downward-sloping curve. d. Wages and some other prices are "sticky". e. Aggregate demand is unstable. f. The goal of macro policy should be to get aggregate demand to go through the "corner" in the aggregate supply curve, or very close to it