In most cases, the us supreme court functions as

a trial court.
a circuit court.
an appellate court.
a superior court.

answer is c

In most cases, the US Supreme Court functions as an appellate court.

Explanation:

The Supreme Court of Justice is the highest court in the United States of America. As such, the Court is the head of the Judicial Power of the United States.

The Supreme Court is the only court established by the Constitution of the United States. All other courts have been created by Congress. The Court has the power of judicial review and the power to declare unconstitutional federal or state laws and acts of the federal and state executive powers. Your decisions can not be appealed.

The Supreme Court, in general, functions as an appellate court in ordinary cases, and as an original court in cases in which States take part.

explanation:

may i ask what challenges?