Answer:
It is capital deepening (D)
Explanation:
Capital deepening typically represents an increase in the capital-labor ratio. This arises when there is infusion of additional capital(e.g technological improvement) into the production processes while work force is either kept constant or cut-down and thereby makes labor to be more productive.
Hence, as the capital-labor ratio increases, the marginal product of labor, i.e. the amount of product that can be produced by supplying one more unit of labor, increases because there are now more units of capital per worker.
