Final answer:
The correct ranking of the federal court system is: District Courts, Circuit Courts of Appeals, Supreme Court.
Step-by-step explanation:
The correct ranking of the federal court system from smallest to largest is: a) District Courts, Circuit Courts of Appeals, Supreme Court.
The lowest level of the federal court system is the District Courts, where federal cases are tried. The next level is the Circuit Courts of Appeals, or U.S. courts of appeals, which review the rulings of the District Courts. And the highest level is the Supreme Court, which has the final authority to interpret the Constitution and the law.