Jasmine was hospitalized with severe abdominal pain and placed in an intensive care unit. Her doctor told the hospital personnel to order around-the-clock nursing care for Jasmine. At the hospital's request, a nursing services firm, Nursing Services Unlimited, provided two weeks of in-hospital care and, after Jasmine was sent home, an additional two weeks of at-home care. During the at-home period of care, Jasmine was fully aware that she was receiving the benefit of the nursing services. Nursing Services later billed Janine for $4,000 for the nursing care, but Jasmine refused to pay on the ground that she had never contracted for the services, either orally or in writing. In view of the facts that no express contract was ever formed, can Nursing Services recover the $4,000 from Jasmine? If so, under what legal theory?