Which blood group an safely be transfused in emergency when there is no time to analyse the blood group of recipient?
Individuals with type O blood do not produce ABO antigens. Therefore, their blood normally will not be rejected when it is given to others with different ABO types. As a result, type O people are universal donors for transfusions, but they can receive only type O blood themselves.
So, the correct option is O and Rh-.'.