The correct answer to this open question is the following.
Although there are no options attached we can say the following.
The judicial branch served as a check on the Executive and Legislative branch in that teh Supreme Court had the power and the faculty to declare a law unconstitutional.
That was the consequence of the judicial review established by the United States Supreme Court in 1803 when it resolved the case Marbury v. Madison.
The Supreme Court could review and decide the constitutionality of decisions made by the Executive branch and the Legislative branch because no action should contradict the Constitution of the United States.
That is the beauty of the checks and balances system in the federal government. That none of the three branches has more power over the other two.
