Correct Option: D

Per capita income or average income or income per person is the mean income within an economic aggregate, such as a country or city. It is calculated by taking a measure of all sources of income in the aggregate (such as GDP or Gross National Income) and dividing it by the total population. Measurement of personal income is the best measure of economic well-being of individuals and nation. Besides, it helps to show the level of inequality in a society or country.