Correct answer:
c. set a precedent with a landmark case
The legal term "precedent" refers to a court decision that establishes a principle or rule. The principle established by the court's decision is used in other cases after that when courts encounter other cases that pertain to similar issues or circumstances. Decisions of a higher court are binding as precedent on any lower courts in the system, so a decision made by the US Supreme Court becomes binding on lower federal courts and state courts.