Which of the Following Is True

Which of the following is true?

A) An accord and satisfaction involves a new party,but a substituted contract does not.
B) Both an accord and satisfaction and a substituted contract involve a new party.
C) An accord and satisfaction discharges the duties under the original contract only when it has been performed,whereas a substituted contract discharges duties under the original contract upon formation of the substituted contract.
D) A substituted contract can occur for any kind of contract but an accord and satisfaction can be used only for contracts for the sale of goods.