Net capital outflow equals the difference between a country's
a. income and expenditure.
b. purchases of foreign assets and sales of domestic assets abroad.
c. investment and saving.
d. purchases of foreign goods and services and sales of goods and services abroad.

B. purchases of foreign assets and sales of domestic assets abroad.

Explanation:

This is the best definition of net capital outflow. Net capital outflow refers to the difference between a country's purchases of foreign assets and sales of domestic assets abroad. This measurement is a good indicator of the general health of an economy. It tells us how much money leaves the country. It also tells us how involved a country is international trade.

answer; the changing age structure of the population;