What is an amendment?

An amendment refers specifically to a change or addition to the Constitution. The U.S. Constitution can be modified through amendments to address new issues, clarify existing provisions, or expand rights. This process honors the founding principle of adaptability within the framework of governance; thus, amendments allow for the Constitution to evolve along with society's values and needs.

The other options represent different concepts within the legal and civic structure. A law passed by Congress denotes a piece of legislation rather than a constitutional change, while a section of the Bill of Rights indicates specific rights and liberties guaranteed to citizens, which are, in fact, amendments themselves. Regulations of state government refer to the administrative rules enacted by state authorities, which do not alter the Constitution but guide state operations. The correct selection captures the essence of what an amendment is within the context of constitutional law.