9 Qui In the Solow model, as investment is assumed to be a constant proportion of output per worker, which of the 1 d following is true? out of Select one: O a. the investment curve has the same shape as the 13 n savings curve. 19 O b. the long run equilibrium is stable. O c. economic growth is possible in the model. 25 O d. the investment curve has the same shape as the 31 3 production function