What Is the Difference Between the Blood Types, A, B

What is the difference between the blood types, A, B, and O?

A) A and B individuals have carbohydrate trees on the surface of red blood cells. O individuals do not have carbohydrate trees.
B) For each blood type, A, B, and O, there is a different sugar attachment enzyme produced.
C) A and B individuals have different modifications made to their carbohydrate tree. O individuals . have no modifications made to their carbohydrate tree.
D) The glycosyl transferase gene has a different mutation in A individuals than in B individuals. O individuals have no mutations in the glycosyl transferase gene.
E) Two of these answers are correct. The glycosyl transferase gene mutations in A and B individuals prevent the removal of carbohydrate trees from the cell surfacE) O individuals have no mutations and therefore have no carbohydrate trees on the red blood cell surface.