Mark offers to design and fabricate a custom mountain bike for Kesha for $500.Mark tells Kesha that the offer can be accepted by fax. Kesha sends a note accepting the offer by regular mail on Monday.Mark tells Kesha on Tuesday that he has accepted Brian's offer to purchase the bike for $750 so the bike is no longer for sale.On Wednesday, Kesha's acceptance is finally delivered.What should the court conclude about this situation