Answer: b. The Tenth Amendment
Delegated powers are those which the US Constitution specifically assigns to the federal government. Reserved powers are those which are reserved for the states -- which ultimately means any powers not specifically granted to the federal government in the Constitution. Any laws and powers exercised by the states still must be in accord with what is stated in the US Constitution, however.
The idea of powers reserved to the states, as opposed to those delegated to the federal government, is stated in the 10th Amendment of the Constitution: "The powers not delegated to the United States by the Constitution, nor prohibited by it to the states, are reserved to the states respectively, or to the people."
