What Is Abstract Constitutional Review

What is abstract constitutional review?

A) Ruling on the constitutionality of a law without any reference to a particular case or how the law has been applied.
B) Ruling on the constitutionality of a law with respect to how it has been applied in a specific instance.
C) A type of constitutional review that can only take place after a law has been in effect for a substantial length of time.
D) A type of constitutional review in which any citizen can bring a case to the court, asserting that a law is unconstitutional.