Original jurisdiction refers to
the supreme court’s authority to hear a case for the first time.
the supreme court’s authority to hear a case from a lower court.
a lower court’s authority to hear a case from the executive branch.
a lower court’s authority to hear a case from the legislative branch.

1. The Supreme Court’s authority to hear a case for the first time.

Explanation:

Original jurisdiction is the Courts' authority to hear a case in the first instance, that is to say, before any appellate review (Appellate jurisdiction). In the United States, there are few cases in which the Supreme Court has original jurisdictions, some of them include all cases affecting Ambassadors, public Ministers and Consuls, controversies between the United States and a State, and inter-state conflicts.

its so obvious. its 999 obviously.