Jack, Karl, and their mother, Erma, owned seventy-eight acres of real property on Bear Creek in Montana. When Erma died, she left her interest in the property to Jack. Jack wrote to Karl offering to buy Karl's interest or to sell his own interest to Karl. He requested that Karl "please respond to Brooke Blue." In a letter to Jacknot to BrookeKarl accepted the offer to buy Jack's interest in the property. By that time, however, Jack had offered to sell his interest to their brother, Don, and he accepted.

-Did Jack and Karl have an enforceable binding contract, entitling Karl to specific performance?

-Or did Jack's offer so limit its acceptance to one exclusive mode that Karl's reply was not effective? Discuss. (See Agreement)