Dr. Salk, a hospital director, calls you in a state of shock. When he has finally calmed down enough to talk coherently, you learn that one of his orderlies came on duty the previous night, as a joke proceeded to exchange wrist bands on the four babies in the nursery, all of whom are the same age. As a first step in unraveling this mess you blood type the parents and babies, with the exception of Mr. and Mrs. Dorsett who refuse to do anything until they have talked with A lawyer. The results of the parents' blood tests are: