Answer:
The most likely option to be a major source of growth in per capita GDP is (a) a high investment/GDP ratio.
A high investment/GDP ratio means that a significant proportion of a country's income is being invested in its economy, which can lead to increased productivity, job creation, and ultimately, higher GDP per capita. Investment can lead to the development of new technologies, the expansion of businesses, and the creation of new industries, all of which can contribute to economic growth. In addition, investment in education, infrastructure, and research and development can also help to increase productivity and create a more skilled workforce, which can further support economic growth.
In contrast, high rates of inflation, rapid growth in the money supply, and rapid population growth are unlikely to lead to sustained increases in per capita GDP. High inflation can lead to a decrease in the purchasing power of a country's currency, which can undermine economic growth. Rapid growth in the money supply can lead to inflation or other economic problems, and rapid population growth can strain a country's resources and make it more difficult to achieve sustained economic growth.