Which of the Following Represents a Valid Accord and Satisfaction

Which of the following represents a valid accord and satisfaction?

A) When a dispute over an unliquidated debt is settled and paid for less than the full amount.
B) When a dispute over a liquidated debt is settled and paid for less than the full amount.
C) When a dispute over an unliquidated debt is settled and paid for the full amount.
D) When a dispute over a liquidated debt is settled and paid for the full amount.
E) When a dispute over either an unliquidated or liquidated debt is settled and paid for less than the full amount.