On November 1, Debbit, an accountant, and Barrister, a lawyer, contracted for the sale by Debbit to Barrister of the law books Debbit had inherited from his father. Barrister agreed to pay the purchase price of $10,000 when Debbit delivered the books on December 1. On November 10, Barrister received a signed letter from Debbit that stated: "I have decided to dispose of the book stacks containing the law books you have already purchased. If you want the stacks, I will deliver them to you along with the books on December 1 at no additional cost to you. Let me know before November 15 whether you want them. I will not sell them to anyone else before then." On November 14, Barrister faxed and Debbit received November 14, Barrister faxed and Debbit received the following message: "I accept your offer of the stacks." Debbit was not a merchant with respect to either law books or book stacks. Debbit is contractually obligated to deliver the stacks because 
Barrister provided a new bargained-for exchange by agreeing to take the stacks. Debbit's letter (received by Barrister on November 10) and Barrister's faxmessage of November 14 constituted an effective modification of the original sale-of-books contract. Barrister's fax-message of November 14 operated to rescind unilaterally the original sale-of-books contract. Debbit's letter (received by Barrister on November 10) waived the bargained-for consideration that would otherwise be required.
Question: On November 1, Debbit, an accountant, and Barrister, a lawyer, contracted for the sale by Debbit to Barrister of the law books Debbit had inherited from his father. Barrister agreed to pay the purchase price of $10,000 when Debbit delivered the books on December 1. On November 10, Barrister received a signed letter from Debbit that stated: "I have decided to dispose of the book stacks containing the law books you have already purchased. If you want the stacks, I will deliver them to you along with the books on December 1 at no additional cost to you. Let me know before November 15 whether you want them. I will not sell them to anyone else before then." On November 14, Barrister faxed and Debbit received November 14, Barrister faxed and Debbit received the following message: "I accept your offer of the stacks." Debbit was not a merchant with respect to either law books or book stacks. Debbit is contractually obligated to deliver the stacks because 
A. Barrister provided a new bargained-for exchange by agreeing to take the stacks.
B. Debbit's letter (received by Barrister on November 10) and Barrister's faxmessage of November 14 constituted an effective modification of the original sale-of-books contract.
C. Barrister's fax-message of November 14 operated to rescind unilaterally the original sale-of-books contract.
D. Debbit's letter (received by Barrister on November 10) waived the bargained-for consideration that would otherwise be required.
Answer: