Which source of criminal law involves implementation by administrative agencies?

Administrative law is the correct answer because it specifically encompasses the body of law created by administrative agencies through their rule-making, enforcement, and adjudicative functions. These agencies have been granted authority by legislatures to create regulations that have the force of law in specific areas, such as environmental protection, labor relations, and health regulations.

In the context of criminal law, administrative agencies may impose sanctions or penalties for violations of their regulations, which are considered a form of criminal law, particularly in areas concerning public welfare. This distinguishes administrative law from other sources of law such as case law, which is developed through court decisions; statutory law, which comprises laws enacted by legislative bodies; and common law, which is based on judicial precedents and practices.

Thus, administrative law plays a unique role in the enforcement of rules established by specialized agencies, making it a vital component of the legal landscape.