Economists use the term fiscal policy to refer to changes in taxing and spending policies
a. by all levels of government, federal, state, and local.
b. only by the federal government.
c. only by state and local governments.
d. by none of the above.

B. Only by the federal government.  

Explanation:

Fiscal policy refers to  alterations in federal taxes and spending which are regulated by the federal government and that are intended to accomplish macroeconomic policy  goals. It began after the Great Depression, when the government was forced to intervene in macroeconomic conditions.

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