Step 1: Understanding the Concept:
The question asks to associate the economist John Maynard Keynes with the appropriate branch of economics.
Step 2: Detailed Explanation:
John Maynard Keynes is widely regarded as the father of modern Macroeconomics. His seminal work, "The General Theory of Employment, Interest and Money" (1936), revolutionized economic thought by focusing on aggregate variables like aggregate demand, national income, and unemployment. He argued for active government intervention to manage the economy, a central theme of macroeconomics.
Step 3: Final Answer:
Keynes is associated with Macro-Economics. Therefore, option (B) is correct.