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. For this question only, assume that on November 12 Debbit told Barrister that he had November 12 Debbit told Barrister that he had decided not to part with the stacks. Will this communication operate as a legally effective revocation of his offer to deliver the stacks? 
Yes, because Barrister had a pre-existing obligation to pay $10,000 for the law books.  Yes, because Debbit was not a merchant with respect to book stacks.  No, because Debbit had given a signed assurance that the offer would be held open until November 15.  No, because by delaying his acceptance until November 14, Barrister detrimentally relied on Debbit's promise not to sell the stacks to anyone else in the meantime. 