Aclassmate tells you that a person can have type ao blood. do you agree

No, there are only four blood types determined by the presence/absence of antigens A and B (A, B, AB, 0).

A blood type-has A antigen on the surface of red cells and B antibody in the plasma

B blood type-has B antigen on the surface of red cells and A antibody in the plasma

AB blood type-has both A and B antigens on red cells but neither A nor B antibody in the plasma

0 blood type-has neither A nor B antigens on red cells but both A and B antibody are in the plasma.

what is the statement?

bradykinin is a physiologically and pharmacologically active peptide of the kinin group of proteins, consisting of nine amino acids.