What is GDP primarily calculated by summing?

Gross Domestic Product (GDP) is primarily calculated by summing net exports, consumption, investment, and government purchases, which together represent the total economic activity within a country over a specific period.

Consumption represents the total spending by households on goods and services, reflecting the overall demand in the economy. Investment accounts for business expenditures on capital goods that will be used for future production, driving economic growth. Government purchases include spending on goods and services that government consumes for providing public services and infrastructure, contributing to overall economic activity. Net exports, which are calculated as exports minus imports, indicate the economic balance between what a country sells to the rest of the world versus what it buys, affecting the overall GDP.

Each of these components is essential in understanding the economic health and productivity of a nation, making option B the correct choice. Other options, while related to economic indicators, do not capture the full measure of economic production like GDP does.