Can a person with positive A donate blood to AB type?

No, a person with A+ blood cannot donate blood to someone with AB+ blood.

A person can only receive a blood transfusion from a donor who has a compatible blood type. The blood type compatibility is determined by the presence or absence of certain antigens on the surface of red blood cells. A person with type A blood has only A antigen, a person with type B blood has only B antigen, a person with type AB blood has both A and B antigens, and a person with type O blood has neither A nor B antigen.

Donated blood must have compatible antigens with the recipient's blood to prevent immune reactions. A person with AB+ blood can receive blood from any type (A+, A-, B+, B-, AB+, AB-, O+, or O-). A person with type B+ can receive blood from type B+ or O+. A person with type A+ can receive blood from A+ or O+.