Read the following scenario. Then, choose the UCC concept (listed below) that you believe is most relevant and explain how it applies.

• Supplier (S) agrees to supply Manufacturer (M) with two barrels of milkshake powder a month using M's formula. Each time M made an order, S sent an acknowledgment letter. After four deliveries, M asked S to change the formula. The change allowed S to make more of the powder at a lower price. S sent M an order acknowledging the higher quantity at a lower price. M did not respond to S's acknowledgment. However, one of M's employees referred to the increased quantity in an e-mail exchange with S. Several months later, after S produced the extra quantities, M stopped using the milkshake powder and refused to pay S for what M had manufactured.
  • Waiver of contract terms.
  • Unconscionability.
  • Breach.