Final answer:
One of the primary purposes of money, as defined by the U.S. Dallas Federal Reserve Bank, is making exchanges. The Federal Reserve ensures suitable currency circulation and conducts monetary policy, affecting economic activity.
Step-by-step explanation:
According to the definition provided by the U.S. Dallas Federal Reserve Bank, one of the primary purposes of money is D. Making exchanges. Money serves as a medium of exchange in the economy, allowing goods and services to be traded efficiently. This fundamental aspect of money facilitates trade by overcoming the limitations of barter, where a double coincidence of wants is required.
The Federal Reserve plays a pivotal role in ensuring that there is enough currency in circulation to meet public demand and in conducting the nation's monetary policy. By managing interest rates and credit conditions through monetary policy, the Fed influences the level of economic activity, thus sustaining a stable financial system.