Q.The definition — "Macroeconomics deals not with individual quantities as such, but with the aggregates of these quantities; not with individual incomes, but with the national income" — is associated with:

The missing term is Income theory. Macroeconomics is popularly called 'Income theory' because its central task is to explain how the level of national income, output and employment is determined.

The correlation contrasts the two branches of economics by their popular nicknames. Microeconomics studies individual units — a single consumer, firm or market — and its main job is to explain how the price of a particular good or factor is fixed by demand and supply; hence it is called Price theory.

Macroeconomics, by contrast, studies the economy as a whole through aggregates such as national income, total employment, the general price level and economic growth. Following the work of J.M. Keynes, its core question became 'What determines the level of national income and employment?' Because income determination sits at its heart, macroeconomics is known as Income theory (or the theory of income and employment).

The correct option is Macro Economics, because it studies the economy as a whole through aggregates.

Macroeconomics (from Greek 'macros' = large) studies the whole economy — total output, national income, aggregate employment, the general price level and economic growth. Microeconomics studies individual units such as a single consumer or firm. Econometrics applies statistics and mathematics to test economic theory, and natural sciences are not a branch of economics at all. Hence the whole economy is studied in macroeconomics.