By outlaying the three branches of the federal government, establishing a bicameral legislature, and defining the relationships between these entities, the U. S. Constitution is fulfilling which of its goals?

The correct answer is separation of powers

This is a model of governance whereby a government is divided into branches, that enjoy separate and independent powers and areas of responsibility so that the powers of one branch are not in conflict with the powers associated with the other branches in order to avoid any branch having excessive powers.