Which One of the Following Is Not Considered by Philosophers

Which one of the following is not considered by philosophers to be a definition of law?

A) Law is a system of rules laid down by a body or person with the power and authority to make law.
B) Law is what legislators, judges and lawyers think the rules should be.
C) Law is a tool for oppression used by the ruling class to advance its own interests.
D) Law is a system of rules grounded in fundamental principles of morality.