Question

which blood type could be given as a transfusion for patient with ab blood when the rh factor is unknown? o+ a+ ab+ ab-

Explanation:

When the Rh factor is unknown, it is safer to use Rh - negative blood for transfusion. AB - negative blood can be given to an AB - blood - type patient (since AB is the universal recipient for ABO system, and using Rh - negative when Rh factor is unknown is a precautionary measure to avoid Rh incompatibility reactions).

Answer:

AB -