Which of these is a case where the original jurisdiction is the federal courts?

United States District Courts

The country is divided into many federal judicial "districts" each with its own US District Court and panel of judges. Any cases emanating from lower courts within the district would begin with that particular "District Court" and then, if necessary, proceed to the US Court of Appeals for [x] Circuit (whatever Circuit the particularly District Court happens to be in). The court with "original jurisdiction" is a trial court, the entry point into the judiciary. For cases of general jurisdiction, the United States District Courts have original jurisdiction over most cases. There are also "special" or "limited subject matter" jurisdiction courts, such as US Tax Court and US Bankruptcy Court that fall under the District Court umbrella (there are many limited subject matter courts that are not part of the District Court system, but these probably hear fewer cases each year). The US Supreme Court also hears a limited number of cases under original jurisdiction, mostly disputes between the states.