what is antigen of blood group A.

for blood group A the antigen will be A and it will have antibodies of B in the blood plasma. and antigens are the surface markers on the red blood cell membrane. and antigens even stimule immune response. antigens can be sugar or protein. they even helps in determining your blood group. and blood groups differs from one person to another in the world. so the antigen will be same as your blood group but only the antibodies will be different