The us federal reserve strengthen the economy when it controls the supply of money, the availability of credit, and

The correct answer is: "the interest rates".

Central banks, such as the Federal Reserve, are in charge of designing and applying the monetary policy, which consists on influencing the amount of money in circulation in the economy and the interest rate levels, through mechanisms such as the open market operations.

These two factors allow to determine the availability of credit in the economy and its investment levels, which in turn determine GDP figures and economic growth levels. The main objectives of the monetary policy are to ensure high economic growth, high employment levels and price stability (low inflation).

interest groups send representatives to state capitals and to washington, d.c. to put pressure on members of congress and other policymakers. they engage in lobbying, or the organized process of influencing legislation or policy. lobbying can take many forms. interest groups can testify in congressional hearings.

a system of cooperative federalism emerged, as the powers of the federal government expanded.