Explanation:

- J.M. Keynes is known as the father of modern macroeconomics. His ideas, especially during the Great Depression, laid the groundwork for understanding economic fluctuations, and he introduced concepts like aggregate demand to analyze economies.

- Adam Smith is often considered the father of economics and capitalism. He is famous for his work "The Wealth of Nations," but he focused more on microeconomics.

- Paul Samuelson was a significant figure in economics and author of a seminal economics textbook, but he isn't specifically known as the father of modern macroeconomics.

- John Hicks was notable in economics for his work on general equilibrium theory, but he is not recognized as the father of modern macroeconomics.