Keeping the Marginal Productivity of Capital Constant While Investment in Plant

Keeping the marginal productivity of capital constant while investment in plant and equipment expands requires

A) a slowdown in the growth rate.
B) a decrease (shift to the left) in the marginal productivity of capital schedule.
C) a falling rate of return on investment.
D) that the productivity of existing technology be exhausted before investing in something new.
E) continued development of new technologies, products, and processes.