The correct answer is C. foreign dignitaries.
The Supreme Court is the most powerful court in the United States - it makes decisions that all other courts don't have the jurisdiction to make. Original jurisdiction means that a court hears a certain case first, without going through lower courts up to higher courts. So, the Supreme Court's original jurisdiction involves cases where foreign dignitaries are involved (foreign diplomats, ambassadors, etc.) and those in which a state is a party.