You have been badly injured in a car accident. It is necessary to give you a blood transfusion because you lost a great deal of blood in the accident. However, special care must be taken in selecting new blood for you. If the blood is too different from your own, the transfusion could kill you. There are four basic types of blood; A, B, AB, and O. A simple test can make sure of a person's blood type. Everybody is born with one of these four types of blood. Blood type, like hair color1 and height, is received from parents. The four groups must be transfused carefully. A and B cannot be mixed. A and B cannot receive AB, but AB may receive A or B. O can give to any other group; therefore, it is often called the universal donor  . For the opposite reason, AB is sometimes called the universal recipient . However, because so many reactions   can happen in transfusions , patients usually receive only salt of plasma (liquid part of blood) until their blood can be matched as exactly as possible in the blood bank of a hospital. In this way, it is possible to prevent the transfusion from any bad reactions. People with type A blood can receive type     .
AB B O all of the three