What Is a Valid Reason for a Court to Accept

What is a valid reason for a court to accept that there is a legally binding contract governing the actions of the parties named to it?

A) Under contract law, each party must get what it bargained for.
B) The parties are permitted to rely on the terms they negotiated.
C) Only the parties to a contract can sue or be sued on it.
D) The contract clearly contains an offer and acceptance of that offer.