Which level of the court system hears appeals from the federal district courts?

The correct choice is the Circuit court of appeals as this is the level of the court system specifically designed to handle appeals from the federal district courts. When a party wishes to challenge a decision made in a federal district court, their case typically goes to one of the twelve regional Circuit Courts of Appeals. These courts review the lower court's decision for errors in the application of law or legal procedure.

The federal supreme court, often referred to as the Supreme Court of the United States, serves as the highest appellate court in the nation but does not directly hear all appeals from the district courts. It selects only a few cases that typically have significant constitutional or federal issues.

A district court is the trial-level court where cases are first heard and decided, making it the starting point in the federal judicial process, rather than an appellate court. The state supreme court addresses appeals arising from the state court system, not federal appellate matters, which is another reason it does not apply here.