Step 1: Understanding the Concept:
Policy actors are divided into official (governmental) and unofficial (non-governmental).
Step 2: Detailed Explanation:
- Official Actors are those with formal legal/constitutional authority: the Executive (D), the Legislature, the Judiciary (B), and Administrators/Bureaucracy (C).
- Unofficial Actors influence policy but lack formal legal authority: Political parties (A), interest groups, media, and citizens.
Step 3: Final Answer:
Political parties are unofficial actors of public policy.