Why is a person with type ab blood able to receive a blood transfusion from a donor with any of the major blood types (a, b, ab, and o) but is able to donate blood only to another type ab individual? match the words in the left column to the appropriate blanks in the sentences on the right.

I believe the correct answer is the presence of antigens.

Red blood cells have specific antigens on their surface that determine the blood group are hereditable. For example, blood group A means the person has the A antigen, B means the B antigen and AB means the person has both A and B antigens. The other group is blood group O and that means the person lacks the antigens to to make a particular blood group. The human body produces other chemicals called antibodies that attacks antigens and that is why you can only recieve a blood group that is yours to prevent the antibodies from attacking you. Since there are only 2 antigens, a person with antigen A produces antibodies against the rival antigen B. In the case of blood group AB where a person has both antigens, the body lacks all the antibodies in order to prevent the body from attacking itself. So a person with blood group AB lacks antigens a and b.This means the person can receive blood from any blood group since there are no antibodies to attack any antigen. They however can only donate to a person who has the same AB bloodgroup since all the other blood groups have antibodies against antigens and adding blood that has antigens will cause a severe blood transfusion reaction.

i think it's the first one because doctors aren't the ones who get rid of the old needles. most of them time it's not even doctors who give you shots, it's nurses.