What role do reserve banks play in the federal reserve system?

The correct answer highlights the function of reserve banks within the Federal Reserve System, which is to hold a portion of commercial banks' deposits. This role is crucial because it helps manage the money supply and ensure the stability of the banking system.

Reserve banks serve as a central entity that collects and manages the required reserves that commercial banks must hold. By holding these deposits, reserve banks can influence the lending capacity of commercial banks and thus impact the overall economy. This mechanism is fundamental in implementing monetary policy and plays a significant role in maintaining liquidity in the banking system.

The reserve banks do not dictate interest rates nationwide; rather, they play a part in influencing them through their operations and the policies of the Federal Reserve. They also do not directly manage federal tax revenues or issue currency to consumers, as these functions are managed at different levels within the government and the Federal Reserve itself. Therefore, option C accurately represents the specific role of reserve banks in the Federal Reserve System.