Samuel Entered into a Contract with AE Lukey Inc

Samuel entered into a contract with AE Lukey Inc.That contract required both parties to perform services.It is now six months later.The contract is executed on one side and executory on the other.Which of the following statements is most likely to be TRUE?

A) One of the parties has sued, but the other party has not.
B) If the parties wish to modify the terms of their contract, they may effectively do so by using the process of accord and satisfaction but not the process of rescission.
C) One party satisfied a subsidiary obligation under a conditional contract.
D) One party has signed the contractual documents, but the other party has not done so.
E) If the parties wish to modify the terms of their contract, they may effectively do so by using the processes of variation or novation without new consideration.