Judy Olsen, Kristy Johnston, and their mother, Joyce Johnston, owned seventy-eight acres of real property on Eagle Creek in Meagher County, Montana. When Joyce died, she left her interest in the property to Kristy. Kristy wrote to Judy, offering to buy Judy's interest or to sell her own interest to Judy. The letter said to "please respond to Bruce Townsend." In a letter to Kristy—not to Bruce—Judy accepted Kristy's offer to sell her interest. Did Judy and Kristy have an enforceable binding contract? Or did Kristy's offer specifying one exclusive mode of acceptance mean that Judy's reply was not effective?