Why countries strive hard to acquire the status of a nation-state ?

D. gave the Supreme Court the power to hear special cases.

Explanation:

The Judiciary Act of 1789 was an act that established a judiciary system made up of district courts, circuit courts, and the Supreme Court, and outlined the structure and jurisdiction of each of the courts.

Regarding the Supreme Court, the statute established that it would consist of one chief justice and five associate justices, that all decisions of its would be final and gave it the power to review court of appeals decisions by writ of certiorari, and to hear special cases such as cases involving disputes between states, convictions for capital crimes, the application of the U.S. Constitution and cases in which a federal law or treaty, or a state constitution or law, was alleged to violate the U.S. Constitution.