Which of the following is one of the constitutional checks on the federal judiciary?

While Congress does have the authority to set and adjust the salaries of federal judges, this action does not serve as a constitutional check on their behavior or decisions. Reducing salaries does not remove judges from office or address judicial misconduct directly.

The president does not have the power to unilaterally fire federal judges. Judges are appointed for life, and their removal requires a process of impeachment by Congress, ensuring that the judiciary remains independent of executive influence.

This requirement is not a constitutional check but rather a qualification for serving as a federal judge. While having a law degree may contribute to a judge's competency, it does not provide a mechanism for oversight or accountability.

Life tenure is a provision designed to protect judicial independence by allowing judges to serve for life, barring impeachment. While it ensures stability in the judiciary, it does not constitute a check on judicial power, as it limits the avenues for holding judges accountable for their conduct.