How does federalism limit national power?

The answer i am positive your looking for is "It creates two sovereigns, the national government and the state governments."

the foundation of greek city-states: following the fall of the mycenaean civilization in the 10th century bc, the area surrounding the empire went through its own mini dark ages. answer and explanation

the right answer is d) a conference committee. it is a temporary panel formed by house and senate members in order to reconcile differences in legislation.