Able raises llamas on his ranch. Many of the llama are very valuable because of their excellent coats. His most prized llama wanders off the ranch. Able is concerned because llamas face many natural predators outside of the ranch. Fortunately, the llama wanders into a neighboring farmer's ranch. The owner of that ranch, Bart, provides food, water and shelter for the llama for seven days until Able is able to retrieve the llama. When Able retrieves the llama he promises to send Bart a check for $250 to compensate Bart for his time an expense in caring for the llama. What is Bart's best argument to enforce Able's promise to pay $250?

That Able's promise was made in recognition of a past benefit provided by Bart to Able.

That Able's promise was bargained for in exchange for Bart's services.

That Bart's services were provide in reliance on Able's promise.

That all promises are legally enforceable.