REF: The IS model. A change in generates a movement along the IS curve; an increase in increases at any given value of R. An increase in shifts the IS curve. Select one: 0 a. R, r,output, aggregate demand, out (9 b. r, R, potential output, aggregate demand, in O c. marginal productivity of capital, r,output,investment, out 0 d. R, r, potential output, aggregate demand, to the left 0 e. R, r,potentia| output, aggregate investment,to the right