In March, a homeowner contracted with a buyer to sell his house for $280,000, with the purchase price to be paid and the deed to be delivered on July 1. On May 1, the buyer wrote the homeowner a letter, stating that she has had second thoughts about buying the house, and she "won't pay that amount of money unless you repaint the house and fix up the yard." If the homeowner wishes to treat the contract as breached: * 0 points (A) He may sue the buyer upon receipt of the letter. (B) He must wait until July 1 to sue the buyer, the date on which the purchase price is to be paid. (C) He must make a written demand to the buyer seeking adequate assurance of performance and wait a reasonable time for a response prior to filing suit. (D) He cannot sue the buyer because the parties' promises are executory at this stage