What Role Do Domestic Courts Play in Enforcing International Law

What role do domestic courts play in enforcing international law?

A) Once ratified,treaties are enforced by domestic courts in the same way as domestic laws.
B) Strong domestic courts give domestic laws precedence,meaning international law may not be enforced by some domestic courts.
C) Domestic courts can overturn international treaty ratification.
D) Domestic courts have little ability to enforce international law because they cannot appeal to international law in legal interpretations.