Which of the following is true about the Tenth Amendment to the Constitution, which provides, "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":
a) It provides the basis for regulation of international trade by a consortium of the states.
b) It offers an absolute bar to the federal government interjecting itself in criminal law.
c) It offers an absolute bar to the regulation of handguns by the states.
d) It offers the most explicit endorsement of federalism to be found in the Constitution.