During 1976 a series of arsons, one of which damaged the Humongous Store, occurred in the City of Swelter. In early 1977 Swelter's City Council adopted this resolution: The City will pay $10,000 for the arrest and conviction of anyone guilty of any of the 1976 arsons committed here. The foregoing was telecast by the city's sole television station once daily for one week. Subsequently, Humongous, by a written memorandum to Gimlet, a private detective, proposed to pay Gimlet $200 "for each day's work you actually perform in investigating our fire." Thereafter, in August 1977, the Swelter City Council by resolution repealed its reward offer and caused this resolution to be broadcast once daily for a week over two local radio stations, the local television station having meanwhile ceased operations. In September 1977, a Humongous employee voluntarily confessed to Gimlet to having committed all of the 1976 arsons. Humongous's president thereupon paid Gimlet at the proposed daily rate for his investigation and suggested that Gimlet also claim the city's reward, of which Gimlet had been previously unaware. Gimlet immediately made the claim. In December 1977, as a result of Gimlet's investigation, the Humongous employee was convicted of burning the store. 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 was benefited as a result of Gimlet's services. 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