Alandlord owned a prestigious downtown office building. a law firm leased the entire building from the landlord for a term of 20 years. the lease included a provision that taxes on the building would be paid by "the lessee, his successors, and assigns." the law firm occupied the building and paid the rent and taxes for eight years. at the end of the eight-year period, the law firm assigned the balance of the lease to an accounting firm and vacated the premises. the assignment was written, but there was no provision concerning the accounting firm's assumption of the duties under the lease. the accounting firm occupied the building and paid the rent and taxes for five years. at the end of the five-year period, the accounting firm subleased the building for five years to an investment company and vacated the premises. the sublease was written, but there was no provision concerning the investment company's assumption of the duties under the lease. the investment company now occupies the building and has paid the rent but not the taxes. the landlord has sued all three (i. e., the law firm, the accounting firm, and the investment company) for failure to pay the taxes. the landlord should prevail against whom? a the law firm only. b the law firm and the accounting firm, but not the investment company. c the accounting firm and the investment company, but not the law firm. d the law firm, the accounting firm, and the investment company.