Answer:
D. one in which power is shared between a central government and state or regional governments.
Step-by-step explanation:
A federal system of government can be defined as a system of government that typically involves splitting (dividing) the power of government into three branches; federal (national) government, state government and local.
Under a federal system of government, each of the branches of government shares power in some areas and have sovereign power in other areas.
In USA, both the federal and state are empowered by the constitution to tax the citizens and migrants living in the country.
Hence, a federal system of government is one in which power is shared between a central government and state or regional governments.
The type of government being practiced in the United States of America is generally referred to as a federal system of government.