An acquired entity has a long-term operating lease for an office building used for central management. The terms of the lease are very favorable relative to current market rates. However, the lease prohibits subleasing or any other transfer of rights. In its financial statements, the acquiring firm should report the value assigned to the lease contract as

  a. An intangible asset under the contractual-legal criterion.
  b. A part of goodwill.
  c. An intangible asset under the separability criterion.
  d. A building.