What governs the set of rules and standards for CNG activities?

The correct answer is the regulations for CNG, as this term encompasses the legal requirements established by governmental bodies that dictate how compressed natural gas activities should be conducted. These regulations are developed to ensure safety, environmental protection, and operational efficiency in the transportation and delivery of CNG. They may include specifications for the construction and operation of CNG delivery vehicles, protocols for handling and storing gas, as well as safety measures that drivers and operators must follow.

In this context, while guidelines, frameworks, and standards of practice can all provide useful guidance for implementing best practices and compliance, they are often considered as supplementary materials rather than the authoritative legal mandates. Regulations carry the weight of law and must be adhered to by anyone operating within the CNG industry, making them the definitive governing rules for CNG activities.