The city, which has no immunity to suit, has since refused to pay Gimlet anything, although he swears that he never heard of the city's repealer before claiming its reward"In a suit by Gimlet against the city to recover the $10,000 reward, which of the following, in light of the facts given, most usefully supports Gimlet's claim?
The city's offer was in the nature of a bounty, so that the elements of contract are not essential to the city's liability. 
The fact that the city attempted to revoke its offer only a few months after making it demonstrated that the attempted revocation was in bad faith.
Although there was no bargained-for exchange between Gimlet and the city, Gimlet's claim for the reward is supported by a moral obligation on the part of the city
The city was benefited as a result of Gimlet's services.