Why Are the Courts Able to Serve as a Before-The-Fact

Why are the courts able to serve as a before-the-fact coordination mechanism for private parties?

A) The federal courts issue binding advisory opinions to definitively tell citizens what is and is not legal.
B) The federal courts offer consultation on the development of legal documents.
C) Individuals anticipate the legal consequences of their actions and, in accordance with the rationality principle, usually make decisions to coordinate in a legal way.
D) Individuals note that the policies of courts, in accordance with the policy principle, will frequently change and that they are thus free to generally do as they wish.
E) Individuals typically do not think about the legality of their actions until just before they are threatened with legal action.