B. It gives specific powers to the federal government.
The United States Constitution grants specific powers and rights to the federal government, called "delegated powers", if it is not outlined in it, then the government should not do it. Furthermore, the Tenth Amendment establishes that all powers that aren't listed in the Constitution are granted to the people or the states. This way, it prevents conflict between federal and state government, and also prevents the government from abusing of its power.
