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:

AB - patients can receive AB - (since RH - is compatible with unknown RH, and AB - has A and B antigens, so AB - blood is safe. O+ has RH +, A+ has RH +, AB+ has RH +, which may not be safe if patient is RH -).

Answer:

D. AB–