Concept:An agglutination test checks whether donated blood is compatible with a patient’s blood before transfusion. It prevents dangerous clumping of red blood cells.
Explanation:Patient X has genotype
AO, meaning blood group
A.
Blood group
A contains anti-
B antibodies in the plasma.
Patient Y has genotype
AB, meaning blood group
AB.
Blood group
AB has neither anti-
A nor anti-
B antibodies.
The same donor blood was given to both patients.
This blood was compatible with patient Y, so no reaction occurred.
But the donor blood must have carried
B antigens, which reacted with X’s anti-
B antibodies.
This caused agglutination, or clumping, of red blood cells in X.
The clumped cells blocked small blood vessels, leading to difficulty in breathing.
Therefore, hospital staff should have performed an agglutination test before transfusing X.
Answer:Patient X should have undergone an agglutination test. (Option A)