The People's Committees led to a high percentage of public involvement in decision making, within the limits permitted by the RCC, but exacerbated tribal divisions. They also served as a surveillance system, aiding the security services in locating individuals with views critical of the RCC, leading to the arrest of Ba'athists, Marxists and Islamists. Operating in a pyramid structure, the base form of these Committees were local working groups, who sent elected representatives to the district level, and from there to the national level, divided between the General People's Congress and the General People's Committee. Above these remained Gaddafi and the RCC, who remained responsible for all major decisions.

Answer this question, if possible (if impossible, reply "unanswerable"): What kind of structure did the People's Committee system use?
pyramid