Which of the following best defines "law"?

The best definition of "law" is encapsulated in the idea that it involves a constitution or statute of a state or the U.S., along with written court opinions. This definition captures the formal and authoritative nature of laws as they are codified and enforced within a legal system. Laws are established by governing bodies and are meant to regulate behavior, set standards, and provide a framework for resolving disputes. They carry the weight of authority and are typically documented in official formats, such as statutes and court decisions, which interpret those laws.

In contrast, other options do not fully embody the essence of law. Local government regulations represent a smaller subset of laws and do not encompass the comprehensive nature of legal frameworks at the state or federal level. Unofficial guidelines lack the enforceable authority of law and can vary widely without legal backing. Similarly, personal codes of conduct are subjective and individual, not representing the structured and community-wide implications of laws that are created and upheld by a governing authority.