When congress doesn't approve a president's choice for a federal court, this is an example of

The best answer to this is checks and balances. Checks and balances is a principle of government under which separate branches are empowered to prevent actions by other branches and are induced to share power. Judicial review on the other hand is one of the checks and balances in the separation of powers. It is the doctrine under which legislative and executive actions are subject to review by the judiciary. Veto, an authority which is considered as one of the most significant tools the President can employ to prevent the passage of legislation. 
The choices of this question are:
A. judicial review
B. checks and balances
C. veto