Final answer:
Blood transfusions require ABO and Rh blood group compatibility to avoid severe reactions. If mismatched, transfusions can lead to symptoms like fever, hives, and low blood pressure.
Step-by-step explanation:
In blood transfusions, compatibility is determined by the ABO and Rh blood groups. Mismatched transfusions can lead to severe reactions. If a person with blood type B receives a transfusion of type A blood, their anti-A antibodies will agglutinate the transfused red blood cells (RBCs) and activate the complement cascade. This can result in fever, chills, hives, hemoglobinuria, and low blood pressure.