On June 1st Jason placed an ad in a local newspaper, to be run on the following Sunday June 6, offering a reward of $100 to anyone who found his wallet. When his wallet had not been returned by June 15, he purchased a new one and started the process to get replacements for his driver license, credit cards and other items. On June 18, Damaris who had seen Jason's ad in the paper, found Jason's wallet, returned it and asked for the $100 reward. Is Jason obligated to pay, why or why not