The answer is letter D. Elites Bureaucrats and the interest groups.
This group is called as the Iron Triangle. The iron triangle consists of the elites, bureaucrats and interest groups. In the United States, Congress plays an important role of the in policy making and laws. Interest groups often represent the constituents of the country. In order to secure a seat in elections, the groups would often asked help from the bureaucrats and elites. These groups of people are important figures in the government. In order to gain their support, the interest groups would often help the elites and bureaucrats in terms of policies that will benefit a certain sector of the population.