Answer: Congress approves Supreme Court Judges
Step-by-step explanation:
The three branches of government in the United States have checks and balances on their power so that they do not exercise absolute power which can lead to tyranny.
In the case of the Legislative and the Judiciary, the Supreme Court can rule an Act of Congress to be unconstitutional and Congress gets a check on the Judiciary because the Senate is the one that approves the appointment of a Supreme Court Judge after the President nominates them.