On May 1, Jennings, a car dealer, e-mails Wheeler and says, "I have a 1955 Thunderbird convertible in mint condition that I will sell you for $13,500 at any time before June 9. [Signed] Peter Jennings." By May 15, having heard nothing from Wheeler, Jennings sells the car to another. On May 29, Wheeler accepts Jennings's offer and tenders $13,500. When told Jennings has sold the car to another, Wheeler claims Jennings has breached their contract. Is Jennings in breach? Explain.