Tenant rented a commercial building from Landlord, and operated a business in it. The building's large front window was smashed by vandals six months before expiration of the Tenant-Landlord lease. Tenant, who was obligated thereunder to effect and pay for repairs in such cases, promptly contracted with Glazier to replace the window for $2,000, due 30 days after satisfactory completion of the work. Landlord was then unaware of the Tenant-Glazier contract. Glazier was aware that the building was under lease, but dealt entirely with Tenant. Sixty days after Glazier's satisfactory completion of the window replacement, and prior to the expiration of Tenant's lease, Tenant, then insolvent, ceased doing business and vacated the building. In so doing, Tenant forfeited under the lease provisions its right to the return of a $2,000 security deposit with Landlord. The deposit had been required, however, for the express purpose (as stated in the lease) of covering any damage to the leased property except ordinary wear and tear. The only such damage occurring during Tenant's occupancy was the smashed window. Glazier's $2,000 bill for the window replacement is wholly unpaid. Assuming that Glazier has no remedy quasi in rem under the relevant state mechanic's lien statute, which of the following would provide Glazier's best chance of an effective remedy in personam against Landlord? 
An action in quasi contract for the reasonable value of a benefit unofficiously and non-gratuitously conferred on Landlord. An action based on promissory estoppel. An action based on an implied-in-fact contract. An action as third-party intended beneficiary of the Tenant-Landlord lease.