Answer: Option B) Antigens
Blood typing is based on the presence of proteins known as antigens on the outer surface of the red blood cell plasma membrane.
Explanation:
Blood groups A, B, AB, and O are determined based on the antigen-antibody reactions between donor and recipient bloods.
For instance,
- Blood type A has antigen A on its plasma membrane
- Blood type B has antigen B on its plasma membrane
- Blood type AB has both antigen A and antigen B on its plasma membrane
- while blood type O has neither antigen A nor B on its plasma membrane
So, antigens is the answer
