Who holds concurrent powers? a. the federal government
b. the state governments
c. both the federal government and state governments
d individual citizens

Concurrent powers are powers shared by the federal government and the states.

Explanation:

The Union's industrial and economic capacity soared during the war as the North continued its rapid industrialization to suppress the rebellion. In the South, a smaller industrial base, fewer rail lines, and an agricultural economy based upon slave labor made mobilization of resources more difficult.