Federalism is:

A. not a component of the US Constitution.

B. patriotism towards one's country.

C. a system in which two or more governments share power over the same constituents.

D. a system that gives the federal government most of the powers in the country.

I believe the answer might be C:

Federalism limits government by creating two sovereign powers-the national government and state governments-thereby restraining the influence of both. Separation of powers imposes internal limits by dividing government against itself, giving different branches separate functions and forcing them to share power.