The correct answer is B. District Courts.
B. District Courts have original jurisdiction over nearly all civil and criminal cases heard in federal courts, since these are courts that, together with the Courts of Appeal and the Supreme Court of the US, conform the Federal Judicial System. They have been set up in each of the fifty states and the District of Columbia. There are ninety-three in all.
Moreover, the other answers are incorrect because:
A. Admiralty courts hear cases of maritime issues.
C. Circuit Courts and D. State Courts have jurisdiction only over state matters, since they depend on the State Judicial System.