What Role Does the Judicial Branch Play in a Nation

What role does the judicial branch play in a nation that uses a common law system?

A) In common law, the judicial branch determines if laws passed by Congress are viable and legitimate.
B) The judicial branch establishes a set of laws through precedent in a common law system.
C) In a common law system, the judicial branch does not play much of a role at all.
D) Under a common law system, the judicial branch is responsible for enforcing laws set by Congress.