Answer:
The correct option is;
D. Irrigation systems have been installed
Explanation:
The quality of capital measures the amount of capital available within an economy and the benefit derivable from the capital
Quality of capital is improved by advances in technology which are the outcomes of research and development. With technological advancement, a unit of capital can enable a unit of labor to increase the amount of goods produced
The difference between a farm which uses manual labor to water the plants and a farm which uses an irrigation system is that the farm that uses manual watering techniques has a lower quality of capital per worker than the farm that has an irrigation system, which is a positive investment.
