[Appendix material: calculus required] Suppose total benefits and total costs are given by B(Y) = 150Y ? 10Y2 and C(Y) = 5Y2. Then marginal costs are: 

Which of the following will NOT shift the Keynesian short-run aggregate supply curve?

A) a change in input prices B) a change in technology C) a change in the price level D) a change in profit expectations

The theory underlying demand and supply curves assumes that, all other things unchanged, the primary variable that assures the equality of the quantities demanded and supplied is:

A) consumer income. B) the preferences of consumers. C) the expectations of consumers and producers. D) price.