Explanation:

- Option 1: Keynes

- John Maynard Keynes is known for Keynesian economics, which emphasizes government intervention in managing economic cycles.

- He countered Say's Law by proposing that demand drives supply, especially during recessions.

- Option 2: Pigou

- Arthur Pigou was a British economist known for his work on welfare economics.

- He focused on externalities and economic welfare, not directly related to Say's Law.

- Option 3: J. B. Say

- Jean-Baptiste Say, a French economist, proposed the idea that "supply creates its own demand."

- This idea became known as Say's Law, suggesting that production inherently creates market demand.

- Correct Answer: J. B. Say

- Option 4: Adam Smith

- Adam Smith is known as the father of modern economics.

- He focused on the invisible hand and free markets but did not specifically propose Say's Law.