Which of the following is an aspect of iron triangles?

fluid participation among interests

a great deal of competition for access to decision-makers

a symbiotic relationship among Congressional committees, executive agencies, and interest groups

three interest groups that have formed a coalition

A symbiotic relationship among Congressional committees, executive agencies, and interest groups.

Explanation:

Iron triangle is a United States political term used to describe the relationship between congressional committees, bureaucracy, and interest groups when a decision needs to be made between the three.

In the iron triangle, Congress, bureaucracy and interest groups establish a partnership relationship, where each seeks to protect and benefit each other, and to assist each other in their policies and objectives. For this reason, the correct answer to your question is: "a symbiotic relationship among Congressional committees, executive agencies, and interest groups."