Which of the Following Provides the Best Example of Discharge

Which of the following provides the best example of discharge by accord and satisfaction?

A) A customer prepays for 5 kilograms of prime rib,but cancels the order because he instead wants to buy 25 kilograms of filet mignon for a business party.
B) A butcher's shop changes ownership and the new owner fills the outstanding orders.
C) A butcher fills his order two days late because he was seriously ill.
D) A butcher runs out of Grade AAA beef and offers Grade A as a substitute (with a good discount) to all customers with existing orders.
E) A butcher's shop burns down and the owner is not able to fill his orders.