How is the federal court system structured?

The federal court system has three main levels: district courts (the trial court), circuit courts which are the first level of appeal, and the Supreme Court of the United States, the final level of appeal in the federal system.

Explanation: The federal court system has three main levels: district courts (the trial court), circuit courts which are the first level of appeal, and the Supreme Court of the United States, the final level of appeal in the federal system.

the answer is the last option or letter d)