Final answer:
The federal district courts are courts of original jurisdiction.
Step-by-step explanation:
The correct answer is:
a. are courts of original jurisdiction.
The federal district courts are the trial courts of the federal system and have original jurisdiction, which means they hear cases for the first time. They are the courts where federal cases are tried, witness testimony is heard, and evidence is presented. There are ninety-four U.S. district courts in the fifty states and U.S. territories, and each district court has a single judge who oversees the cases.