One of the reasons Henry Clay believed a national bank was needed was to

The correct answer is: to stabilize prices and the U. S. economy.

Explanation:

Henry Clay believed the National bank was necessary in order to stabilize the U. S. economy. That's why he decided to include the National Bank in the American system (his economic plan to protect and stabilize the American industry and economy). The National Bank also could control the flow of money and currencies and give subsidies to businesses that were planned for expanding American industrialization.

He also saw the National Bank as an opportunity to create a strong monetary policy and prevent inflation by stabilizing prices.