B. Cooperative federalism has been practiced in the US since 1860.
Cooperative federalism, or the concept of federalism in which local, state, and federal governments work together to create policies, replaced dual federalism in the 1930s.
http://www.beaconlearningcenter.com/documents/5215_4498.pdf
<3
The Huns contributed to the fall of the Western Roman Empire with:
C. They conquered and burned Rome
AND
E. They drove Germanic people into the Empire
