The available blood supply is just one pint each of
A+, AB-, B-, and O+. Which pint must each of the four patients receive?
Patient 1:A+,AB-,B-,O+
Patient 2: A+,AB-,B-,O+
Patient 3: A+,AB-,B-,O+
Patient 4: A+,AB-,B-,O+
