Explanation:

- Option 1: J.B. Say

- Correct Answer!

- Jean-Baptiste Say, a French economist, formulated Say's Law, which states that supply creates its own demand.

- He suggested that production inherently generates enough income to create a market for the goods produced.

- Option 2: J.S. Mill

- John Stuart Mill was a philosopher and economist, contributing to utilitarianism and liberalism.

- His work involves political economy and not specifically formulating Say's Law.

- Option 3: Keynes

- John Maynard Keynes was a British economist known for Keynesian economics.

- He challenged Say’s Law, arguing that demand can fall short of supply, leading to recessions.

- Option 4: Ricardo

- David Ricardo was an English economist known for his theory of comparative advantage.

- He did not formulate Say's Law but contributed extensively to classical economics.