Two unconscious patients X and Y whose blood group genotypes are AO and AB respectively were transfused with the blood from the same donor. Patient X immediately showed signs of breathing difficulty while patient Y showed no negative reaction.

Patients X and Y were likely transfused with blood of genotype

A.

OO

B.

AO

C.

BO

D.

AA

Correct answer is C

The blood types A and AB can receive blood from blood types A and O but not B. Hence, if there was a problem after transfusion, it was most likely to be from BO.