In addition to the United States Code, administrative regulations are primarily found in:

The Federal Register is the primary source for federal administrative regulations. It is a daily publication that provides a comprehensive record of all federal agency actions, including proposed rules, final rules, and notices. When agencies create regulations based on the authority granted to them by statutes, they publish those regulations in the Federal Register to inform the public and solicit feedback. This process ensures transparency and allows citizens to engage with the regulatory process.

The other sources, such as state statutes, legislative history, and public law archives, do not serve the primary function of disseminating administrative regulations at the federal level. State statutes pertain to the laws created by individual state legislatures and are distinct from federal regulations. Legislative history can provide context for understanding how certain laws were developed but does not include the regulations themselves. Public law archives may house a variety of legal documents, but they are not specifically focused on the issuance of administrative regulations, which are documented and accessible through the Federal Register. Thus, the Federal Register is the central repository for federal administrative regulations, making it the correct response in this context.