The word "concurrent" refers to powers that a. belong only to state governments b. belong to the national government c. are shared by the states and nation d. are determined only by the president

The answer is C. God bless! Jesus is coming soon.

The answer is 

C. are shared by the states and the nation.

Concurrent powers are powers that are being shared between the US government and the state government. In the United States, examples of the concurrent powers shared by both the federal and state governments include the power to tax, build roads, establish bankruptcy laws, and to create lower courts.