Many greek city-states encouraged migration to areas outside of Greece during the 8th and 7th centuries B.C in order to "<span>c. Establish bases for commercial and military expansions" which the Greeks desperately needed.</span>

So an iron triangle comprises or makes the base of the policy making relation over or among the congressional committees,the bureaucracy, etc.
Hope This Helps!!!
B. THEY WERE PROTESTING THE TEA ACT. a bill that was passed to save the fall of the east india company by lowering its tea tax by a great amount