Rowe was admitted to the hospital suffering from a critical illness. He was given emergency treatment and later underwent surgery. On at least four occasions, Rowe's two sons discussed with the hospital the payment for services to be rendered by the hospital. The first of these four conversations took place that day after Rowe was admitted. The sons informed the treating physician that their father had no financial means but that they themselves would pay for such services. During the other conversations, the sons authorized whatever treatment their father needed, assuring the hospital that they would pay for the services. After Rowe's discharge, the hospital brought this action against the sons to recover the unpaid bill for the services rendered to their father. Are the sons' promises to the hospital enforceable?