Group activity the author would fear

An iron triangle is a lasting, mostly closed relationship among an interest group, the bureaucratic agency that regulates its field and the congressional committee that funds and oversees that agency. Each side helps the others: the group gives political support, the committee gives money and favorable laws, the agency gives helpful rules.

That is the kind of arrangement Schattschneider would distrust most. It lets a narrow, organized interest shape policy out of public view, while the diffuse interests of the wider public have no seat in the triangle.

Each choice

• A. Educating and mobilizing citizens draws more people into politics, which is what the author wishes the group system did. He would be less worried by this than by closed deals.
• B. Only a member of Congress can introduce a bill, so groups cannot do this. The idea also has no link to the author's point about who is excluded.
• C. Representing broad parts of society is the cure for the author's complaint, not a cause of it. His worry is narrow groups, not broad ones.
• D (correct). Iron triangles let narrow organized interests work privately with agencies and committees, shutting out the broad public the author says the system ignores.