Jerry loses his favorite gold wrist watch while at work. He posts signs in the office building where he works and in the adjacent parking garage, offering a $500 reward to anyone who finds the watch and returns it to him. Renee, one of Jerry's co-workers, finds the watch in an office stairwell, recognizes it as Jerry's, and returns it to him, not knowing that Jerry has offered a reward for its return. Choose the best answer:

Jerry owes Renee $500 because she returned the watch in exchange for Jerry's promise to pay $500.

Jerry does not owe Renee $500 because that would be an unfair bargain.

Jerry owes Renee $500 since she returned the watch in reliance on Jerry's promise to pay $500.

Jerry does not owe Renee $500 because she did not return the watch as a bargain for the $500.