Which of the following describes monetary policy?

Monetary policy involves the management of a nation's money supply and interest rates, and it is primarily conducted by the central bank, such as the Federal Reserve in the United States. The ability of the Federal Reserve to implement monetary policy is one of its key functions, and it can do so independently without requiring congressional approval or any external permissions. This allows the Fed to respond quickly to economic conditions, adjusting interest rates or engaging in open market operations to influence the economy's liquidity and stability.

This independence is crucial because it enables the central bank to make timely decisions to combat inflation, support employment, and promote overall economic growth without the delays that might occur if legislative processes were involved. Thus, the description that correctly captures this aspect of monetary policy is that it is a tool of the Federal Reserve which does not rely on external permissions.