A legislative body that has legal sanction to establish agencies can establish which of the following regarding a particular activity or action?

The correct choice is regulations because a legislative body is empowered to create laws and rules that govern specific activities or actions within its jurisdiction. Regulations are binding rules issued by governmental agencies based on the authority granted by legislation. They provide detailed procedures that must be followed to comply with the law, and they often include specific requirements and enforcement mechanisms.

In contrast, best practices, standards, and guidelines do not carry the same legal weight. Best practices are typically established based on expert consensus or through industry norms; they serve as recommendations for achieving optimal results but are not legally enforceable. Standards, while they may inform expectations and practices, can be voluntary or adopted by industries and may not have formal legal backing unless mandated by regulatory processes. Guidelines offer suggested approaches and methods but, like best practices, are not legally binding. Regulations, however, are the formal mechanisms through which a legislative body ensures compliance with laws, making them the only option among the choices that directly involves legal authority.