Macroeconomics emerged as a separate subject in the year _____ due to Prof. J. M Keynes.

1930s

The correct answer is Option (2) → 1930s

Macroeconomics, as a separate branch of economics, emerged after the British economist John Maynard Keynes published his celebrated book The General Theory of Employment, Interest and Money in 1936. The dominant thinking in economics before Keynes was that all the labourers who are ready to work will find employment and all the factories will be working at their full capacity. This school of thought is known as the classical tradition.