Which governmental agency is responsible for regulating the nation's money supply?

The Federal Reserve System is responsible for regulating the nation's money supply. This central banking system manages monetary policy to ensure economic stability and growth. It controls the money supply through various mechanisms, including setting interest rates, open market operations, and reserve requirements for banks. By adjusting these levers, the Federal Reserve can influence inflation, employment rates, and overall economic activity.

In contrast, the Securities and Exchange Commission oversees the securities industry, ensuring that markets operate fairly and transparently, while the Department of Housing and Urban Development focuses on national housing policies and programs. The Federal Trade Commission protects consumer rights and enforces antitrust laws to promote fair competition, rather than controlling the money supply. Therefore, the Federal Reserve is the correct answer as it plays the pivotal role in managing the country's monetary policy.