Which of the following blood group can be the donor for universal donor?

The blood group that can act as the universal donor is blood group O negative (or blood type O-).

In blood group O, there are no A or B antigens on the surface of the red blood cells. Due to this absence of antigens, blood group O does not provoke an immune reaction when transfused into individuals with other blood groups. As a result, people with blood group O are considered universal donors.