Jimmy $,$ a chef, needed his food truck repaired. He told his friends that he would give $$500$ to the first

person who fixed his truck. Milly was first to begin the repairs to Jimmy's truck. Unfortunately, justas she

finished the job, a neighbor's dog bit her and she had to go to the emergency room for a couple of stitches.

Jimmy has refused to pay Milly on the basis that the agreement was not in writing and that Milly ended up

being $"$an inexperienced repair person". Which of the following is an appropriate characterization of the

agreement between Jimmy and Milly?

They had a bilateral, express contract.

They had a bilateral, implied contract.

They had a voidable quasi contract.

They had a unilateral contract.